Custom Packaging Box Materials Guide

Custom Packaging Box Materials Guide: White Card, Greyboard, Kraft, Corrugated

Every packaging property you care about, stiffness, print, sustainability, and cost, starts with the board. This guide compares the four workhorse materials, white card (SBS/FBB), greyboard, kraft, and corrugated, with the real numbers buyers use to specify them.

White card: SBS and FBB

White card is the bright, clean face stock of folding cartons. SBS (solid bleached sulphate) is white through and through and prints at 300 dpi with excellent colour. FBB (folding boxboard) has a mechanical-fibre middle with a white top, giving more stiffness per gram, which is why a 350 gsm FBB carton feels as rigid as a heavier SBS one. Typical grammages run 250 to 450 gsm; below 250 gsm the carton can flute on the shelf.

SBS versus FBB in practice

Choose SBS when the interior must be bright white, as in confectionery or cosmetics where the inside shows. Choose FBB when you want stiffness at lower weight and cost, accepting a slightly cream interior. Both take offset, digital, and foil well, and both reach a Delta E under 2-3 with G7 calibration.

Greyboard: the rigid core

Greyboard, or chipboard, is the recycled core of every rigid box. It comes in 0.8, 1.0, 1.2, 1.5, 2.0, 2.5, and 3.0 mm, with density 0.65 to 0.70 g/cm3. The grammage converts as thickness times density times 1000, so 1.5 mm is about 1020 gsm, 2.0 mm about 1360 gsm, and 2.5 mm about 1700 gsm. The surface is speckled, so it is always wrapped; the wrap, not the core, is what the customer sees and prints on.

Choosing greyboard thickness

Light gifts use 1.0 to 1.2 mm; cosmetics and electronics 1.5 to 2.0 mm; heavy or luxury 2.5 to 3.0 mm. Tolerances are plus or minus 0.5 mm on finished size, widening to plus or minus 1.0 mm on large boxes. The core also sets magnet and hinge placement because the V-groove is cut to about half the board thickness.

Kraft: the natural fibre look

Kraft is unbleached sulphate or recycled fibre with a warm brown tone. It reads eco and pairs with soy inks and simple flexo or screen print; offset and digital can print on it but the colour shifts warmer. Grammages for cartons run 250 to 400 gsm, and for corrugated liners the board is rated by flute. Kraft is fully recyclable and compostable as paper, which makes it the default for brands leading with a sustainability story.

Kraft limits

Kraft shows fibre and impurities, so it is poor for bright white photography. Fine type in a light colour can disappear into the grain. Use it where the natural look is the point, not where clinical brightness is required.

For more on this, see Custom Poker Cards.

Corrugated: fluted protection

Corrugated is a liner plus a fluted medium. E flute is about 1.5 mm and prints acceptably for retail shippers; B and C flutes at 3 to 4 mm give stacking and drop protection. The flutes create an air column that absorbs impact, which is why corrugated, not rigid greyboard, is the transit material. Liners can be kraft or white, printed by flexo or offset.

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Material properties at a glance

Convert greyboard mm to gsm at density 0.68 g/cm3 for fair comparison.

Matching material to product

For a premium folding carton, FBB at 350 gsm balances stiffness and cost. For a rigid box, a 1.5 mm greyboard core with a 157 gsm coated wrap is the standard luxury build. For an eco carton, kraft 300 gsm with soy ink. For transit, B or C flute corrugated sized to the load. The decision tree is at /blog/how-to-choose-the-right-packaging-box and the white-card detail at /blog/white-card-box-packaging-guide-2026.

Sourcing and certificates

• Request FSC chain-of-custody for white card and kraft.
• Ask for recycled content percentage on greyboard and kraft.
• Confirm grammage by ISO 536 sampling, not supplier claim.
• Specify soy or low-VOC inks for the eco story.