Paperboard Grades for Folding Cartons: SBS, FBB, Kraft and Recycled Board Selection Guide

Paperboard Grade vs GSM vs Caliper

Paperboard grade, GSM and caliper answer different questions. The grade or board family describes the material construction and market specification. GSM measures mass per square meter. Caliper or PT describes physical thickness. Two boards can share a similar GSM and still differ in thickness, stiffness, coating, reverse shade or folding behavior because their fiber structure and manufacturing route are different.

This is why a quotation should not say only “350 gsm” when board family matters. A more controlled request identifies the board direction and then records the GSM or caliper that will be approved for that project.

For the detailed GSM/PT measurement and conversion topic, use the paper weight, GSM and PT guide. This article keeps the focus on board-family selection rather than repeating the conversion tables.

Main Paperboard Families for Folding Cartons

The board families below are useful sourcing directions, not universal performance classes. Exact stiffness, bending behavior, compression, crack resistance and product-load suitability depend on the finished carton and the approved material.

SBS / Solid Bleached Board

SBS stands for Solid Bleached Sulfate in U.S. spelling and Solid Bleached Sulphate in British spelling. They refer to the same board-family term. In current HSPACK material references, SBS-style or white paperboard is used as a print-oriented direction for folding cartons and selected cosmetic cartons.

The practical reason buyers consider this family is usually the clean white printing surface and suitability for high-detail branded graphics. That does not create a universal strength rating. The result still depends on carton dimensions, product weight, structure, grain direction, crease design, ink coverage, coating, finish and the approved sample.

Current HSPACK pages include 300–400 gsm C1S ivory references for cosmetic folding cartons and broader 250–400 gsm C1S/C2S art-paperboard options on the folding-carton commercial page. These are current sourcing directions, not an “SBS strength chart,” and the exact supplied grade should be confirmed in the project specification.

FBB / Folding Box Board

FBB means Folding Box Board. It is a recognized board-family term used in international paperboard sourcing. It should be treated as a technical family request, not as proof that a specific FBB mill grade is currently in HSPACK stock.

When a buyer asks for FBB, the next step is to confirm the supplier or mill specification, GSM or caliper, surface, reverse shade, grain direction and the actual carton use. If the inquiry uses ivory board, ask whether that market term refers to an FBB product, another C1S white board or a different local specification.

For HSPACK sourcing, use the control TERM_MAPPING_REQUIRES_PROJECT_CONFIRMATION: the material can be discussed as a board family, but exact availability and construction must be confirmed for the quotation and sample.

Kraft Paperboard

Kraft board is another market term rather than one globally identical construction. Current HSPACK commercial references include natural brown, white, black and coated kraft directions, with common listed GSM options of 250, 300, 350 and 400 gsm for current kraft-carton projects.

The base color changes artwork behavior. A brown kraft substrate can shift printed colors compared with a white board. White ink, foil, embossing, debossing and other premium effects may be possible in selected projects, but they should be treated as PROJECT_DEPENDENT and SAMPLE_REQUIRED.

For the commercial kraft-carton range, use the kraft boxes page. N04 remains the board-family selection guide rather than the kraft product owner.

Recycled, CCNB, Grey-Back and Duplex Terms

Recycled paperboard, CCNB and grey-back board can be discussed as material directions, but the exact supplied construction matters. The current HSPACK evidence does not confirm a standard recycled-board stock range, fixed recycled-content percentage or universal application performance.

Duplex board is especially important to clarify. In different markets it can refer to a grey-back coated recycled board, while in another packaging context “duplex” may describe a mounted or laminated construction. Those are not automatically the same material. Ask the supplier to describe the face, reverse, fiber or mounted construction and the exact quoted grade.

If recycled content, recyclability or certification is part of the buying requirement, request the applicable project document. Do not infer a percentage or environmental claim from the word recycled, kraft or paperboard alone.

Board Surface and Printing

The print face is often as important as the board-family name. Current HSPACK folding-carton production supports offset printing, CMYK and project-level Pantone work, but the selected paperboard surface determines how color, fine detail and finishes will appear.

• White coated surfaces: often provide a cleaner base for high-detail retail graphics.
• Kraft surfaces: can change the visible color result because the substrate is not a neutral white base.
• C1S / C2S: describe coating direction, not a mill grade; keep coating designation separate from board-family mapping.
• Recycled / grey-back directions: require the print face and reverse appearance to be confirmed in the actual sample.

A print proof or material sample is the safest reference when strict brand color matters. Do not assume a process is suitable on every board only because the factory offers that process elsewhere.

Stiffness, Grain and Creasing Are Project Variables

Board-family names should not be converted into fixed stiffness, bending or compression values without the exact material and test method. Folding-carton behavior comes from the combination of board construction, GSM/caliper, grain direction, carton geometry, crease setup, ink coverage, coating, finish and the packed product.

Grain direction is particularly important on thick or heavily finished cartons because it can change folding smoothness and visible score cracking. The correct grain and crease relationship should be reviewed with the dieline and physical sample rather than treated as a universal rule.

If a project is already showing cracking or whitening at the folds, move to the folding carton score cracking guide. That page owns the defect-diagnosis topic; N04 only explains why the material choice must be validated with the crease.

Which Board Family Fits Which Product?

Product categories can help frame the discussion, but they cannot determine the final grade by themselves. A small lightweight cosmetic carton and a larger glass-jar carton may both use white paperboard while needing different structures, GSM/caliper, crease settings or outer shipping protection.

For commercial carton structures and quotation, continue to custom folding cartons. For the basic definition, anatomy and style overview, use what is a folding carton.

Finishes and Coatings

Current HSPACK folding-carton capabilities include lamination, foil stamping, embossing, debossing and Spot UV directions, but every material/finish combination is PROJECT_DEPENDENT. Board surface, coating, ink coverage, fold location, glue area and the required visual effect can all change the result.

• Confirm whether the finish crosses a critical crease.
• Keep glue zones compatible with the coating or lamination route.
• Approve foil, embossing or Spot UV placement on the selected board.
• Use a physical sample where fold cracking, scuffing or tactile finish matters.

Common Paperboard Specification Mistakes

• Using grade and GSM as the same thing: grade is the material family; GSM is mass per area.
• Writing SBS = white card = FBB: these terms should not be collapsed into one global material.
• Using “ivory board” without a supplier specification: it is a market term that can refer to different white-board constructions.
• Using “duplex board” without defining the construction: grey-back recycled board and duplex-mounted board are not automatically the same.
• Assuming a higher GSM guarantees performance: carton size, structure, grain, crease, product weight and the approved sample still matter.
• Assuming every finish works on every board: print and finish compatibility is project-specific.
• Making sustainability claims from the material name: kraft, recycled or FSC-related wording requires the applicable project evidence.
• Approving artwork before the board and crease are stable: material changes can alter folds, print and finish behavior.

Folding Carton Board Selection Worksheet

Use the worksheet below to compare candidate boards on the same project inputs. It is a sourcing record, not an automatic performance calculator.

Sample Approval Before Mass Production

The physical sample closes the gap between a grade name and the real carton. Record the actual board used in the approved sample so repeat orders do not rely on a vague market term.

1. Confirm the exact board family or supplier grade used for the sample.
2. Record GSM and/or caliper as applicable.
3. Confirm grain direction and crease performance.
4. Check the carton with the actual product or controlled product dummy.
5. Approve CMYK/Pantone color and any lamination, foil, emboss/deboss or Spot UV.
6. Check glue, closure and folding after the finish is applied.
7. Record the approved board and sample revision for the production order.

For sample-route differences, use the packaging sample guide. A digital visual does not prove the final board feel, fold behavior or production finish.

Paperboard Grade RFQ Checklist

A comparable paperboard quotation should connect the requested board to the actual folding-carton project.

• Product: dimensions, weight and photos.
• Carton: finished size, structure, opening direction and packing method.
• Board direction: SBS, FBB, kraft, recycled/CCNB or another specified family if known.
• Market term: if using white card, ivory or duplex board, ask the supplier to define the exact construction.
• GSM / caliper: provide a target only if already approved; otherwise let the factory propose it separately from the grade.
• Printing: CMYK, Pantone, inside printing, coverage and color reference.
• Finishes: lamination, foil, emboss/deboss, Spot UV or other specified process.
• Grain / crease: confirm where fold quality or cracking risk is important.
• Documentation: food-contact, FSC-related, recycled-content or other project files only when required.
• Sample approval: define what the physical sample must confirm before production.

The broader packaging material selection guide should be used when the buyer has not yet decided between paperboard, corrugated, rigid or protective packaging. N04 assumes the project is already in the folding-carton paperboard family.