Materials / Paperboard reference
Paperboard reference
SBS, clay-coated chipboard, kraft-back, and plain chipboard in one place: what the calipers mean, what each grade is for, and a quick stack calculator for pads, partitions, and rigid box builds. One point equals 0.001 inch.
Caliper converter
Enter a caliper in points to convert to inches and millimeters. One point equals 0.001 inch.
Caliper0.018 in (0.457 mm)
Tolerance: board caliper is typically held to about plus or minus 5 percent, and laminated or printed sheets gain a little thickness. For tight-fitting trays and rigid box wraps, spec the caliper on the purchase order and confirm against the mill certificate.
Working notes
Grain directionScores fold cleanest with the grain; plan carton grain parallel to the main score lines
Score allowanceHeavier calipers need wider creasing rules; 24 pt and up often needs a double score
Print surfaceC1S coats one side, C2S coats both; chipboard backs print poorly without a liner
SBS calipers and typical uses
Solid bleached sulfate, the premium white board for retail packaging.
| Points | Inches | mm | Best use in design |
|---|---|---|---|
| 10 | 0.010 | 0.25 | Inserts, lids, lightweight sleeves |
| 12 | 0.012 | 0.30 | Pharma cartons, small folding cartons |
| 14 | 0.014 | 0.36 | Standard folding cartons, sleeves |
| 16 | 0.016 | 0.41 | Cosmetics cartons, heavier sleeves |
| 18 | 0.018 | 0.46 | Blister cards, club-pack cartons |
| 20 | 0.020 | 0.51 | Heavy cartons, header cards |
| 24 | 0.024 | 0.61 | Rigid-feel cartons, heavy blister, hang tags |
| 28 | 0.028 | 0.71 | Extra-heavy cards, tiers, small displays |
Board families compared
| Grade | Surface | Typical range | Pick it for |
|---|---|---|---|
| SBS (C1S / C2S) | Bright white, premium print | 10–28 pt | Retail cartons, blister cards, luxury packaging |
| CCNB chipboard | Clay-coated face, gray back | 16–30 pt | Economical cartons, cereal-box construction |
| CUK / CNK kraft back | Coated face, kraft back | 14–24 pt | Beverage carriers, strength with moisture exposure |
| Uncoated chipboard | Gray both sides, no coating | 20–60 pt | Pads, backers, partitions, rigid box cores |
Chipboard for structure
| Points | Inches | Best use in design |
|---|---|---|
| 22 | 0.022 | Pads, layer sheets, mailer stiffeners |
| 30 | 0.030 | Backers, partitions, tier sheets |
| 40 | 0.040 | Rigid box walls, easel backs, riser cores |
| 50 | 0.050 | Heavy rigid boxes, structural display parts |
| 60 | 0.060 | Premium rigid setup boxes, book-style bases |
Grades and calipers here reflect common converting practice; every mill runs its own deck. When a build mixes boards, spec each part's grade and caliper separately, since a 40 pt chipboard core wrapped in 12 pt SBS behaves nothing like a single 52 pt sheet.