Introduction
Your packaging is often the first physical touchpoint between your brand and your customer. The paper you choose can make a box feel premium, reliable, and well-made — or thin, weak, and forgettable.
The challenge is that most buyers compare numbers like 300gsm, 350gsm, or 16pt without knowing what those numbers mean in real packaging production. A box may look good in a sample but crack at the fold line. A paper bag may feel luxurious but fail under product weight. A hang tag may look thick on paper but bend too easily in hand.
This guide explains GSM, caliper, paper weight, board type, and common packaging uses so you can choose materials that print well, fold cleanly, protect the product, and match your brand positioning.
For packaging, buyers should compare GSM together with caliper, paper type, stiffness, coating, grain direction, printing method, folding performance, and product weight. The right paper thickness depends on the packaging type, such as folding boxes, paper bags, hang tags, inserts, rigid boxes, or corrugated boxes.
What Does GSM Mean in Paper?
GSM means grams per square meter. It is a measure of paper weight, or grammage, that shows how much one square meter of paper weighs.
For example, 350gsm paper means one square meter of that paper weighs 350 grams.
GSM is used in most international paper and packaging specifications because it gives buyers, designers, printers, and packaging manufacturers a standard way to compare paper weight across different materials and suppliers.
For early material selection, GSM is still one of the fastest and most practical ways to narrow down paper options, especially when comparing papers from the same material category.
However, GSM measures weight, not exact thickness. A higher GSM usually means a heavier sheet, but actual caliper, stiffness, surface feel, and folding performance can still vary by paper type, density, coating, fiber, and manufacturing process.
What Is Paper Thickness?
Paper thickness, also called caliper, measures the physical depth of a sheet of paper, cardstock, or paperboard from one surface to the other. It is commonly measured in microns, millimeters, or points, depending on the market and material type.
| Measurement | Meaning |
|---|---|
| Micron | One-thousandth of a millimeter |
| Millimeter / mm | A metric unit used to measure actual thickness |
| Point / pt | Commonly used for cardstock and packaging board thickness |
| Caliper | A technical term for the measured thickness of paper or board |
While GSM tells you paper weight, thickness helps you understand how the material may feel, bend, fold, score, cut, and perform in a packaging structure.
For packaging, paper thickness can affect stiffness, hand feel, durability, folding, scoring, cutting, die-cutting, and overall packaging structure.
A folding box needs enough thickness to hold its shape, but it also needs to fold cleanly. A hang tag needs enough stiffness to feel premium. A paper bag needs enough strength to carry weight. A packaging insert needs the right thickness to hold the product securely in place.
Extra thickness can improve structure, but it can also create production problems if the material does not match the design. Very heavy or rigid board may be harder to fold, score, or die-cut, and it may crack along fold lines without proper scoring.
The goal is to choose a material that fits the product, structure, printing method, finishing process, and final packaging use.
How to Measure Paper Thickness
Paper thickness is usually measured with a caliper or micrometer. These tools measure the physical depth of the sheet and give the result in millimeters, microns, points, or another thickness unit.
For very thin paper, measuring one sheet may not be accurate enough. In this case, suppliers may measure a stack of sheets and divide the total thickness by the number of sheets to get a more reliable average thickness.
For example, if 100 sheets measure 10 mm in total thickness, the average thickness of one sheet is about 0.10 mm.
For packaging projects, buyers should confirm both GSM and actual thickness, especially for folding cartons, sleeves, hang tags, inserts, paper bags, and rigid box wrap paper.
Common Paper Weight Examples: GSM, LBS, and Typical Uses
The table below gives a quick reference for common paper weights used in office printing, commercial printing, cardstock, and packaging. These values are approximate because LBS depends on the paper category, while GSM is based on grams per square meter.
| Paper / Stock Type | Common Weight | Approx. GSM | Typical Uses |
|---|---|---|---|
| Standard copy paper | 20 lb bond | 75gsm | Office printing, documents, internal sheets |
| Premium printer paper | 24–32 lb bond | 90–120gsm | Reports, letterheads, proposals |
| Text paper | 60–80 lb text | 89–118gsm | Booklets, brochures, flyers, catalogs |
| Heavy text paper | 100 lb text | 148gsm | Premium brochures, menus, magazine pages |
| Light cover stock | 65–80 lb cover | 176–216gsm | Cards, covers, light product cards |
| Heavy cover stock | 100–110 lb cover | 271–298gsm | Postcards, tags, backing cards |
| Extra heavy cover stock | 130 lb cover | 352gsm | Premium cards, hang tags, luxury print pieces |
| Paperboard | 250–350gsm | 250–350gsm | Folding cartons, retail sleeves, packaging boxes |
Paper Thickness Chart for Packaging: GSM, mm, pt, and Common Uses
The chart below gives a general reference for common paper weight and thickness ranges used in packaging. It helps buyers compare GSM with approximate caliper in millimeters and points.
Actual paper thickness can vary by paper type, density, fiber, coating, calendering, moisture content, and manufacturing process. Use these numbers as a starting reference, not as a fixed production specification.
| GSM Range / Board Type | Approx. Thickness / Caliper | Approx. PT | Common Packaging Uses | Buyer Notes |
|---|---|---|---|---|
| 35–70gsm paper | 0.04–0.08 mm | 1.5–3 pt | Tissue paper, wrapping paper, decorative inner sheets, light liners | Very thin and flexible. Best for wrapping or decoration, not structural packaging. |
| 70–120gsm paper | 0.08–0.15 mm | 3–6 pt | Manuals, instruction sheets, leaflets, lightweight printed inserts | Check opacity, print clarity, folding performance, and show-through. |
| 120–170gsm paper | 0.12–0.20 mm | 5–8 pt | Flyers, brochures, belly bands, light sleeves, promotional inserts | Flexible and printable, but may feel too thin for premium cards or rigid sleeves. |
| 170–250gsm cardstock | 0.20–0.30 mm | 8–12 pt | Product cards, backing cards, light hang tags, thank-you cards, small sleeves | Offers better stiffness than regular paper. Check flatness, hole strength, and surface finish. |
| 250–300gsm paperboard / cardstock | 0.30–0.38 mm | 12–15 pt | Light folding cartons, retail sleeves, product cards, small packaging boxes | Common for lightweight packaging. Check scoring, grain direction, and product weight. |
| 300–350gsm paperboard / cardstock | 0.35–0.46 mm | 14–18 pt | Folding boxes, cosmetic boxes, skincare cartons, premium cards, medium hang tags | A common range for retail packaging. Confirm caliper, stiffness, lamination, and fold-line cracking risk. |
| 350–400gsm cardstock / specialty board | 0.42–0.55 mm | 16.5–22 pt | Premium hang tags, luxury product cards, rigid sleeves, specialty packaging parts | Feels thicker and more premium, but may be harder to fold, score, or die-cut into small details. |
| 400gsm+ specialty board | 0.50 mm+ | 20 pt+ | Heavy hang tags, thick cards, premium inserts, display pieces | Better for flat or simple structures. For folded packaging, scoring and grain direction are critical. |
| Greyboard / chipboard | 1.0–4.0 mm | 39–157 pt | Rigid boxes, setup boxes, gift boxes, luxury packaging structures | Usually specified by board thickness, not GSM. Check board stability, wrap paper, edge quality, and corners. |
| Corrugated board | About 1.5–7.0 mm depending on flute | 59–275 pt | Mailer boxes, shipping boxes, e-commerce boxes, protective packaging | Specify flute type, liner quality, board grade, compression strength, and shipping requirements. |
Use this chart as an early screening tool, not a final production specification. Before confirming a packaging material, ask your supplier for the actual caliper, board type, coating or surface finish, grain direction, and sample sheet.
Then test the material in the real packaging structure. Check printing, scoring, folding, die-cutting, assembly, product fit, and whether the finished package feels right for your brand.
Is GSM the Same as Paper Thickness?
No. GSM is not the same as paper thickness.
GSM measures weight. Paper thickness measures physical depth. The two measurements are related, but they cannot replace each other.
This does not mean GSM is useless. Within the same material family, GSM is often the most efficient first filter for comparing paper weight, cost direction, and general material level before checking actual caliper and performance.
For packaging decisions, use GSM to shortlist the material level, then use caliper, stiffness, surface finish, and sample testing to decide whether the material actually works.
When comparing two 300gsm or 350gsm papers, do not approve the cheaper option by grammage alone. Ask for the actual caliper, paper type, coating, bulk, and printed sample before making the final choice.
Here is a simple comparison:
| Term | What It Measures | Common Use |
|---|---|---|
| GSM | Weight per square meter | Comparing paper weight |
| Thickness / Caliper | Actual thickness of paper | Measuring physical depth |
| PT / Point | Thickness unit | Cardstock and packaging board |
| Micron | One-thousandth of a millimeter | Paper, film, and board thickness |
| LBS | U.S. basis weight | Common in the U.S. paper market |
For packaging buyers, the final question is not only “What GSM is it?” but “Will this material print, score, fold, assemble, and protect the product in the finished package?”
Why Can Two Papers with the Same GSM Feel Different?
When two suppliers quote the same GSM, the materials may still perform differently in production. This is why buyers should compare more than the number on the specification sheet.
Before choosing between two papers with the same GSM, request the caliper, bulk, coating, fiber or board construction details, and sample sheets. Then compare how each material prints, scores, folds, die-cuts, and feels in the finished package.
For example, a 350gsm kraft paperboard and a 350gsm coated white paperboard may have the same weight per square meter, but they can behave very differently when printed, folded, scored, die-cut, or used for a retail box.
Several factors can affect how paper feels and performs:
| Factor | How It Affects Paper Feel and Performance |
|---|---|
| Fiber type | Different fibers can change strength, texture, and flexibility |
| Paper density / bulk | Denser paper may feel smoother and more compact; bulkier paper may feel thicker. |
| Coating | Coated paper often feels smoother and supports sharper printing |
| Calendering | Compresses and smooths the paper surface, which can reduce bulk |
| Surface finish | Glossy, matte, uncoated, textured, and kraft finishes all feel different |
| Recycled content | May affect strength, color, texture, and stiffness |
| Moisture content | Can influence flexibility, flatness, and dimensional stability |
| Paperboard structure | Different board constructions affect folding, scoring, and stiffness |
| Manufacturing process | Influences density, smoothness, caliper, and durability |
Density and Bulk: How They Change Paper Feel
Density describes how compact a paper is. In simple terms, it shows the relationship between paper weight and paper thickness. A denser paper may feel smoother, thinner, and more compressed, while a lower-density paper may feel thicker, softer, or more porous even when the GSM is the same.
Bulk describes how much volume or thickness a paper has compared with its weight. A high-bulk paper is usually more porous and may feel thicker or stiffer. A low-bulk paper is usually more compact and may feel smoother or denser.
For packaging buyers, bulk and density help decide the final hand feel. Choose a higher-bulk paper when you want a thicker, softer, or more tactile impression. Choose a denser paper when you need a smoother surface, sharper printing, or a more compact material feel.
Before approval, compare printed samples side by side instead of judging by GSM alone.
Quick Packaging Material Guide by Use
After checking the paper thickness chart above, use this quick guide to narrow down the right material family for your packaging project.
- Tissue paper and wrapping sheets: Choose lightweight paper when the goal is decoration, wrapping, or inner presentation rather than structural support.
- Manuals, leaflets, and instruction sheets: Use standard printing paper with good opacity, foldability, and print clarity.
- Product cards, backing cards, and hang tags: Choose cardstock when the piece needs better stiffness, cleaner edges, and a more premium hand feel.
- Folding cartons and retail sleeves: Use paperboard or heavier cardstock when the packaging needs to hold shape, print well, score cleanly, and fold without cracking.
- Paper bags: Choose kraft paper, coated paper, or specialty paper based on bag size, product weight, handle type, bottom structure, and reinforcement needs.
- Rigid boxes: Specify greyboard or chipboard thickness instead of GSM alone. Also check wrap paper, corner quality, edge finish, and overall structure.
- Packaging inserts: Choose paperboard, corrugated board, molded pulp, or specialty board based on product fit, protection level, and unboxing presentation.
- Corrugated mailers and shipping boxes: Specify flute type, board grade, liner quality, compression strength, product weight, and shipping distance. GSM alone is not enough for shipping packaging.
Buyer takeaway: After choosing the material family, ask your supplier for two or three practical options based on your product weight, packaging size, artwork, finishing method, and target price. Compare the options by structure, print result, hand feel, and production risk before moving into mass production.
Paper, Cardstock, Paperboard, Cardboard, and Corrugated Board: What’s the Difference?
Paper, cardstock, paperboard, cardboard, and corrugated board are all paper-based materials, but they are not the same. Paper is thin and flexible, cardstock is thicker and stiffer, paperboard is used for printed packaging structures, cardboard is a broad everyday term, and corrugated board has a fluted layer for cushioning and shipping strength.
In packaging, using the correct material name matters. Each option has different thickness, stiffness, printability, folding behavior, strength, and protection performance. Many buyers use these terms interchangeably. For example, a customer may call a folding carton, rigid gift box, or shipping box a “cardboard box.” In production, however, these materials are not always interchangeable.
| Material | Simple Definition | Common Packaging Use |
|---|---|---|
| Paper | Thin, flexible sheet material with limited structural strength | Manuals, leaflets, labels, wrapping paper, and decorative layers |
| Cardstock | Thicker and stiffer than regular paper, but less structural than paperboard | Hang tags, backing cards, product cards, belly bands, and thank-you cards |
| Paperboard | Thick paper-based board used for packaging structures | Folding cartons, sleeves, retail boxes, cosmetic boxes, and food boxes |
| Cardboard | A broad everyday term for thick paper-based packaging materials | Often used casually to describe paperboard boxes, rigid boxes, or shipping boxes |
| Corrugated board | Multi-layer board made with liner paper and a fluted medium | Mailer boxes, shipping boxes, e-commerce boxes, and transport packaging |
Paper
Paper is the thinnest and most flexible material in this group. It is usually used for printed or decorative parts that do not need to carry weight or hold a packaging structure.
In packaging, paper is commonly used for instruction sheets, manuals, leaflets, wrapping paper, labels, lightweight inserts, and inner decorative layers.
Cardstock
Cardstock is thicker and stiffer than regular paper. It feels more durable in the hand and is often used when a printed piece needs to keep its shape.
In packaging, cardstock works well for hang tags, product cards, backing cards, thank-you cards, belly bands, and small sleeves. It is a good choice when you need something stronger than paper but not as structural as paperboard.
For more details, read our cardstock paper guide to compare cardstock weight, thickness, printing, and packaging uses.
Paperboard
Paperboard is commonly used for packaging structures. It offers better stiffness and shape retention than paper or cardstock, while still being suitable for printing, scoring, folding, and die-cutting.
Common uses include folding cartons, retail boxes, product sleeves, cosmetic boxes, food packaging boxes, and other custom printed packaging. Different paperboard types, such as SBS, FBB, kraft paperboard, recycled paperboard, and CCNB, can produce different print results, surface feel, stiffness, and folding performance.
Cardboard
Cardboard is a common everyday word, but it is not always precise in professional packaging.
Customers may use “cardboard” to describe cereal boxes, gift boxes, folding cartons, rigid boxes, or shipping boxes. In production, it is better to use the specific material name. A folding carton may use paperboard, a rigid box may use greyboard or chipboard, and a shipping box usually uses corrugated board.
Corrugated Board
Corrugated board is made with liner paper and a fluted medium. The fluted layer gives the board cushioning, rigidity, and stacking strength.
It is commonly used for mailer boxes, shipping boxes, e-commerce packaging, subscription boxes, and transport packaging.
For corrugated packaging, request a complete board specification instead of asking for GSM only. A useful quote should include flute type, liner quality, board grade, ECT or burst strength, box size, product weight, and shipping distance.
Common flute types include:
| Flute Type | Approx. Board Thickness | General Feature | Common Packaging Use |
|---|---|---|---|
| E-flute | About 1.5–2.0 mm | Fine flute, thinner board, better print surface | Lightweight mailer boxes, retail boxes, and small e-commerce packaging |
| B-flute | About 2.5–3.0 mm | Medium flute with a balance of strength and printability | Standard shipping boxes and general product packaging |
| C-flute | About 3.5–4.0 mm | Thicker flute with stronger cushioning | Larger shipping boxes and protective packaging |
| BC-flute | About 6.0–7.0 mm | Double-wall board combining B-flute and C-flute | Heavy-duty shipping, long-distance transport, and heavier products |
These thickness ranges are general references only. Actual corrugated board thickness can vary depending on flute profile, liner paper, board grade, compression, and production process.
In short, paper is mainly for flexible printed parts, cardstock is for stronger cards and tags, paperboard is for printed packaging structures, cardboard is a broad everyday term, and corrugated board is built for shipping protection.
After choosing the general material family, buyers should also confirm the exact paper or board type. SBS C1S, SBS C2S, CCNB, kraft paper, textured paper, grey chipboard, and metallic paper can all perform differently in print quality, folding, finishing, structure, and hand feel.
Use the related material guides to compare specific paper types before confirming the final packaging specification.
GSM vs LBS: How to Compare Paper Weight Across Markets
Now that the material types are clear, the next confusion comes from the numbers themselves. A supplier quotes 80 lb cover. Another quotes 220gsm paperboard. Which one is heavier, thicker, or better for your package? The answer is not always obvious because GSM and LBS use different measurement systems.
As explained earlier, GSM is a more direct measurement of paper weight: grams per square meter. It gives buyers a consistent way to compare paper weight across suppliers, countries, and paper types.
LBS, or basis weight, works differently in the U.S. paper system. The lb number only makes sense when you know the paper category, because text, book, cover, bristol, and other papers are not calculated from the same basis size.
Basis weight means the weight of 500 sheets in a standard parent sheet size for a specific paper category.
Text, book, cover, bond, index, and bristol papers use different basis sizes, so the same lb number can describe very different materials.
Quick Conversion Reference
Use this table as a rough reference when comparing U.S. basis weight with GSM for common packaging materials.
| If Your Supplier Quotes This | Rough GSM Equivalent | Common Packaging Use |
|---|---|---|
| 50–80 lb text | 70–120gsm | Instruction sheets, manuals, and leaflets |
| 70–115 lb text | 100–170gsm | Flyers, brochures, and lightweight sleeves |
| 75–90 lb cover | 200–250gsm | Product cards, backing cards, and light tags |
| 90–130 lb cover | 250–350gsm | Folding cartons and retail boxes |
| 110–150 lb cover | 300–400gsm | Premium hang tags and specialty cards |
| Paper bag materials | Usually specified by GSM, paper type, and load | Paper bags, shopping bags, and retail carry bags |
| Corrugated board | Usually specified by flute type and board grade | Mailer boxes and shipping boxes |
Quick mental conversion:
Text / book paper: GSM ≈ lb × 1.5
Cover paper: GSM ≈ lb × 2.7
These are rough estimates for quick mental math. For a faster and more accurate comparison, use our paper weight conversion calculator to convert LBS to GSM or GSM to LBS by paper category.
How to Handle an LBS Quote
Step 1: Confirm the category.
Ask whether the quote refers to text, book, cover, bristol, or another paper type. Without this, the lb number is incomplete.
Step 2: Convert to a rough GSM range.
Use the table above to place the quoted lb value into context. This helps you compare suppliers from different markets more easily.
Step 3: Test the sample in your actual structure.
Fold it, score it, and print on it. A GSM or LBS conversion helps compare weight, but the sample shows how the material behaves in production.
For international packaging projects, GSM is usually easier to compare than LBS. After the weight unit is clear, the next step is to check how the material behaves in printing, folding, scoring, die-cutting, and finishing.
How Paper Thickness Affects Printing and Finishing
Paper thickness affects more than how a material feels. It can also influence how the paper prints, folds, scores, cuts, die-cuts, and accepts special finishes.
This is especially important in packaging because the material is rarely used as a flat sheet only. It often needs to be printed, folded into shape, cut into a custom structure, and finished with decorative or protective effects.
Printing Quality
Paper thickness is only one part of print quality. Surface smoothness, formation, brightness, whiteness, opacity, coating, and base color can also affect the final result.
A smoother paper surface usually supports sharper details, cleaner lines, and more even ink coverage. Good formation helps reduce blotchy color, especially in large solid-color areas, gradients, or brand-color backgrounds.
Brightness and whiteness affect contrast and color appearance. A bright white coated paperboard can make printed colors look cleaner and more vivid, while kraft, black, recycled, or colored paperboard will change how the final color appears.
Opacity is also important for manuals, inserts, product cards, sleeves, and double-sided printed materials. Higher opacity helps reduce show-through, so text and artwork from one side are less visible on the other side.
For packaging buyers, the key point is simple: the paper surface, base color, opacity, coating, and printing method should match the artwork and final packaging use.
Folding and Scoring
Thicker paperboard usually needs scoring before folding. Scoring creates a controlled crease line so the material can fold cleanly and consistently.
Grain direction is also important. Paper usually folds more smoothly along the grain direction and may crack more easily when folded against the grain. This matters for folding cartons, sleeves, belly bands, rigid box wrap paper, paper bags, and other packaging structures with sharp folds.
Humidity and dimensional stability can also affect production. If paper expands, shrinks, or warps during printing or finishing, it may cause registration, folding, or die-cutting problems.
Before approving the material, test the actual dieline with the selected paperboard, ink coverage, lamination, and grain direction. Check whether the carton folds smoothly, closes correctly, and avoids cracking along the score lines.
Cutting and Die-Cutting
Paper thickness also affects how accurately a material can be cut or die-cut.
Thin paper is usually easier to cut, but it may not provide enough strength for structural packaging. Thick paperboard feels stronger, but it requires more precise tooling, stronger die-cutting pressure, and careful structural design.
Very thick board is not suitable for tiny details, narrow gaps, sharp corners, small windows, delicate tabs, or complex locking structures. In these cases, the dieline and material thickness should be planned together.
Special Finishing
Paper thickness and surface finish can affect how well the material accepts special finishes, including:
- foil stamping
- embossing
- debossing
- spot UV
- stamping embossing
- textured embossing
- lamination
- water-based coating
- soft-touch lamination
- varnish
For example, foil stamping often works best on smooth and stable paperboard surfaces. Embossing and debossing usually need enough material thickness to create a visible raised or recessed effect. If the paper is too thin, the effect may look weak or may deform the sheet.
Spot UV can create contrast between glossy and matte areas, but the surface coating and paper smoothness can affect the final result. Lamination can improve protection and surface feel, but it may also increase the risk of cracking on fold lines if the material is not scored properly.
For the best result, paper thickness, surface finish, printing method, finishing process, and packaging structure should be planned together.
How to Choose Paper Thickness for Different Packaging Types
Paper thickness affects each packaging type differently. For some packaging, it supports structure and protection. For others, it affects folding, carrying strength, print appearance, or perceived value.
Start with the job the packaging needs to perform. Does it need to display, carry, protect, ship, organize, or create a premium unboxing experience?
Once the function is clear, choose the paper thickness based on product weight, packaging size, structure, printing method, finishing process, and shipping requirements.
Quick Buyer Decision Guide: Which Paper Thickness Should You Choose?
Use this table as a quick starting point before reviewing product weight, packaging structure, printing, finishing, and shipping requirements in more detail.
| Buyer Situation | Recommended Material Direction | What to Check Before Production |
|---|---|---|
| Lightweight printed insert or manual | 70–120gsm paper | Print clarity, folding, opacity, and whether the sheet feels too thin |
| Product card or backing card | 250–350gsm cardstock | Flatness, stiffness, hole strength, surface finish, and print clarity |
| Folding carton for light products | 250–350gsm paperboard | Scoring, folding performance, box size, product weight, and fold-line cracking |
| Premium hang tag | 300–400gsm cardstock or specialty board | Stiffness, hole strength, edge quality, foil stamping, embossing, or spot UV |
| Paper bag for retail products | 80–350gsm kraft paper, coated paper, or specialty paper | Carrying weight, handle support, bottom structure, reinforcement, and lamination |
| Rigid box | 1–4 mm greyboard / chipboard + 128–200gsm wrap paper | Board thickness, structural strength, edge quality, wrap paper, and finishing effect |
| E-commerce mailer or shipping box | Single-wall, double-wall, or triple-wall corrugated board | Flute type, liner quality, compression strength, product weight, and shipping distance |
| Packaging insert | 250–400gsm paperboard, corrugated board, molded pulp, or specialty board | Product fit, stability, cushioning, thickness, and presentation effect |
| Sleeve or belly band | 157–200gsm medium-weight paper or 250–350gsm cardstock, depending on product size and wrapping fit | Wrapping fit, flexibility, folding performance, print quality, and product size |
Use this table for initial material selection. Final specifications should be checked against the actual product, structure, artwork, finishing, and shipping requirements.
Folding Boxes
For folding boxes, paper thickness must balance stiffness and foldability.
The board should be strong enough to hold the carton shape, but flexible enough to fold cleanly along scored lines.
If the board is too thin, the carton may bend, collapse, or feel weak. If it is too thick, it may be harder to fold, close, or assemble, and the fold lines may crack without proper scoring.
For many light-to-medium folding cartons, 250–350gsm SBS C1S, C2S, kraft paperboard, or similar paperboard is a common starting range. A 350gsm SBS C1S carton can provide good stiffness and print quality, but the final choice still depends on product weight, box size, scoring, lamination, and internal support.
For heavier or more fragile products, such as glass bottles or candle jars, the carton may also need a stronger board, corrugated insert, reinforced structure, or a different packaging solution.
Key checks include board type, product weight, grain direction, scoring quality, ink coverage, lamination, internal support, and fold-line cracking risk.
Rigid Boxes
Rigid boxes depend more on structural board thickness than GSM alone.
Unlike folding cartons, rigid boxes are usually made with greyboard or chipboard, then wrapped with printed or decorative paper. The inner board creates strength and shape retention. The wrap paper creates the surface color, texture, print effect, and finishing style.
Key checks include board thickness, wrap paper quality, edge wrapping, corner quality, and surface finish.
Paper Bags
For paper bags, thickness affects carrying strength, handle support, bottom stability, folding quality, and brand feel.
A lightweight boutique bag does not need the same paper specification as a large shopping bag for heavier retail products. Bag size also matters because width, depth, height, gusset, and product weight all affect material choice, handle strength, and bottom support. If you are still confirming bag size, see our guide on how to measure paper bag dimensions.
However, GSM is only one part of bag strength. A paper bag can still fail if the handle area, bottom construction, glue, or reinforcement design is weak.
Key checks include handle support, bottom structure, glue quality, reinforcement design, surface finish, and tear resistance.
Corrugated Boxes
For corrugated boxes, thickness is not about a single sheet of paper. It comes from the board structure, including liner paper and the fluted middle layer.
For lightweight cosmetic mailers, a fine flute may improve print appearance. For heavier or fragile products, the priority should shift to board strength, compression performance, cushioning, and protective inserts.
A cosmetic mailer, subscription box, glass bottle shipper, and heavy product shipping box may all need different corrugated specifications.
Key checks include flute type, liner quality, board grade, stacking or compression strength, product fragility, shipping distance, and storage conditions.
Hang Tags
For hang tags, thickness mainly affects perceived quality, stiffness, durability, and hole strength.
A thin tag can bend easily and feel less premium. A thicker cardstock or specialty board can make apparel, jewelry, cosmetics, gifts, and handmade products feel more refined.
But the tag should still match the product and tag size. Very thick cardstock can look bulky on a small tag, increase cost, or make string attachment less practical.
Key checks include tag size, hole strength, attachment method, edge quality, die-cut shape, and finishing effects.
Packaging Inserts
For packaging inserts, thickness affects product fit, stability, protection, and presentation.
A thin paper insert may be enough for lightweight products or simple display. A thicker paperboard insert can help hold cosmetics, bottles, candles, electronics, or gift sets more securely. Corrugated inserts may be better when cushioning and shipping protection are more important.
The insert should hold the product in place without making the box difficult to pack, close, or open.
Key checks include product shape, product weight, slot design, insert material, cushioning needs, and unboxing presentation.
Key Questions Before Choosing Paper Thickness
Before confirming GSM, caliper, or board thickness, first ask what the packaging needs to do.
| Question | Why It Matters |
|---|---|
| What product are you packaging? | Different products need different levels of strength, stiffness, protection, and presentation. |
| How heavy or fragile is the product? | Heavy or fragile products may need stronger board, inserts, cushioning, or corrugated protection. |
| Will it be shipped or displayed in-store? | Shipping needs durability and compression strength; retail display needs clean printing and shelf presentation. |
| What brand feeling should the packaging create? | Kraft paper, coated board, textured paper, and thick rigid board create different customer impressions. |
| What printing or finishing will be used? | Foil stamping, embossing, spot UV, lamination, and full-color printing can affect material choice. |
| What should the sample test confirm? | A sample should confirm print color, folding, scoring, finishing, product fit, assembly, and real-use performance before mass production. |
In short, the best paper thickness is not the thickest option. It is the material that fits the product, supports the structure, prints well, folds cleanly, protects properly, and performs reliably in real use.
FAQ About Paper Thickness and GSM
GSM means grams per square meter. It measures paper weight, not exact thickness.
For example, 300gsm paper means one square meter of that paper weighs 300 grams.
No. GSM measures paper weight, while paper thickness, or caliper, measures the physical depth of the sheet.
In simple terms, paper weight tells you how heavy the sheet is, while paper thickness tells you how thick the sheet actually is. Two papers with the same GSM can still have different thickness, stiffness, texture, and folding performance.
Not always. Higher GSM usually means heavier paper, but actual thickness also depends on density, fiber, coating, surface finish, and manufacturing process.
This is why packaging buyers should compare both GSM and actual caliper.
There is no fixed thickness for 300gsm paper. A 300gsm coated board, kraft board, recycled board, or high-bulk board can all have different caliper and stiffness.
For accurate packaging specifications, ask your supplier for the actual caliper or sample sheet.
It depends on the packaging type, product weight, structure, printing method, finishing process, and final use.
Folding cartons, paper bags, hang tags, rigid boxes, inserts, and corrugated boxes all require different material choices.
Yes, especially for custom packaging. A physical sample helps confirm whether the selected material prints well, folds cleanly, fits the product, and feels right before mass production.
Paper thickness is usually measured with a caliper or micrometer. For very thin paper, suppliers may measure a stack of sheets and divide the total thickness by the number of sheets to calculate the average thickness.
Standard printer paper is commonly around 75–90gsm, often described as 20 lb or 24 lb bond paper in the U.S. This range is suitable for everyday office printing, documents, and internal sheets.
Final Thoughts
Choosing the right paper thickness is not about picking the heaviest or thickest material. The best choice depends on your product weight, packaging structure, printing method, finishing process, shipping conditions, and the final brand experience you want to create.
GSM is a useful starting point, but reliable packaging specifications come from matching the material to the actual product, structure, artwork, finishing process, and production method. This is where supplier experience matters: the right material should not only look good on paper, but also print, fold, assemble, protect, and feel right in real use.
Need help choosing the right paper weight or board thickness?
Share your product size, weight, artwork, packaging style, and order quantity with EPACK. Our team can help compare suitable paperboard, kraft paper, rigid board, corrugated board, printing, and finishing options for your custom packaging project.
