Custom Blister Card Packaging

What a Carded Blister Has to Get Right

A blister card has two jobs that pull against each other. The clear cavity has to hold the product tight enough that it does not rattle, and the printed card has to hang flat on a peg for months without tearing at the hole.

Most failures we see trace back to three numbers set too early: the card size, the board caliper and the hang hole. This page covers how we work those out for a carded blister, from the clearance inside the cavity to the strip of board above it that carries the weight.

Backing Card Sizes and Cavity Fit

The sizes below are typical planning sizes. Exact card and cavity dimensions are set to your product at quoting.

Card size (in)	Metric (mm)	Typical contents	Typical caliper	Cavity note
4 x 6	102 x 152	Charging cables, small fastener packs, nail accessories	14-18 pt SBS	Shallow face-seal cavity
4 x 7	102 x 178	Drill bit sets, picture-hanging kits, small hand-tool parts	18-20 pt SBS or coated kraft	Extra height for hang area and copy block
5 x 7	127 x 178	Earbuds, memory card packs, phone accessories	18-20 pt SBS	Contoured cavity common
5 x 8	127 x 203	Lash kits, brush sets, beauty tools	18-22 pt SBS	Multi-cell cavity for kit pieces
6 x 9	152 x 229	3.75 in scale action figures, chargers with cords	20-24 pt SBS	Often deeper than 1 in, so sample first
8 x 12	203 x 305	6-7 in figures, multi-piece sets	22-24 pt, often full-face or trapped	Deep cavity, structural sample needed

Work outward from the product. Leave 1/16 to 1/8 in of clearance on each face inside the cavity: tighter and the item will not seat, looser and it rattles and flexes the cavity in transit. A face-seal blister then needs a flat flange of roughly 7 mm (about 0.28 in) around the cavity to bond to the card.

Here is a worked example. A product measuring 2.5 x 4.5 in gets a cavity of about 2.75 x 4.75 in. Add the flange on every side and the footprint reaches roughly 3.3 x 5.3 in. On a 4 x 7 in card that leaves about 0.35 in of board at each side and about 1.7 in of height to split between the hang area at the top and the copy block at the bottom.

Card Board and Caliper

Caliper is board thickness in points, and 1 pt equals 0.001 in. A 14 pt card is 0.014 in thick and weighs roughly 300 gsm; an 18 pt card lands around 350-400 gsm. Mills hold caliper to a tolerance of about plus or minus 5 percent, so expect small variation across lots.

• 14 pt SBS: fine for light items on small cards. A thin card under a heavy cavity is more likely to tear at the hang hole.
• 18-20 pt SBS: the usual range for hardware, electronics and beauty cards in the 4 x 7 to 5 x 8 in sizes.
• 22-24 pt SBS: for 6 x 9 in cards and up, deeper cavities and products that pull on the peg. Across the trade, 22 pt is the workhorse caliper for carded hardware and toys.
• Coated kraft: a brown face with a coated print side, chosen by tool and outdoor brands.
• Recycled paperboard: available, but post-consumer content depends on the mill, so confirm the figure before printing it.

The card also needs a heat-seal coating where the flange lands. An aqueous heat-seal coat is applied over the print in the seal zone; a card carrying only a standard print varnish will not bond reliably. Grain direction matters too: board is stiffer across the grain, so we set the grain to resist the card bowing forward under the cavity.

Hang Hole Options for Peg Display

The hang hole carries the whole pack, so pick it with the product weight and the retailer fixture in mind.

• Round punch: the simplest hole and fine for light cards. Load concentrates at one point.
• Euro slot: a wide slot with a raised center that spreads the load along its top edge. A common Euro hole geometry is about 30 mm wide.
• Delta hole: a triangular cut that can hold better than a round hole on some fixtures.
• J-hook strip: used for heavier items where a punched hole would tear.

Keep the hole well away from the top edge, since a hole close to a thin edge tears first. For heavier packs the top of the card can be doubled by folding and gluing a header panel before the hole is die-cut. Above all, confirm the peg type against the retailer planogram before artwork is final.

Blister Construction Options

• Face-seal: the cavity flange is heat-sealed to the front of one card. The lowest-cost construction, but not advised for heavy products.
• Full-face seal: the plastic runs out to the card edges, giving a larger seal area for heavier items.
• Trapped blister: the cavity sits between a front and back card that are sealed card to card. Both faces print, and a die-cut opening in the back card makes the product easier to remove.
• Full-card blister: the plastic wraps around the card edges instead of being sealed to it.
• Slide blister: the cavity slides into a card rail, so the pack can be opened and refilled.
• Heat-sealed unit-dose card: a front and back card sealed around single doses, opened once.

An all-plastic hinged clamshell is a separate format that resists pilfering better but is harder to open.

Cavity Forming

Cavities are vacuum-formed from a flat sheet pulled over a mold. Small retail cards commonly use film around 10 to 15 mil. Very flat items under roughly 1/4 in tall form poorly, so they usually suit a skin pack or a card with a window instead.

A simple rectangular or oval cavity is the quickest to tool. A contoured cavity follows the product outline, and a multi-cell cavity holds a figure plus accessories. Anything deeper than about 1 in behaves differently in forming and sealing, so we confirm it on a physical sample before the run. For film choice, see the blister pack materials blog post.

Printing and Finishing the Card

Backing cards print in CMYK with optional Pantone spot colors, on offset for steady artwork or digital for short runs and regional variants. Gloss or matte aqueous coating, UV coating, spot UV and foil are available on the open card area.

Plan the seal zone before the artwork. Laminations and some coatings will stop the flange from bonding, so they stop short of the flange line. Fine type, barcodes and regulatory copy also sit clear of the seal, because the plastic edge distorts anything printed underneath. The finish catalog of custom boxes blog explains each finish.

Who Orders Carded Blisters

• Hardware and tools: bits, fasteners, hanging kits and replacement parts on peg walls.
• Electronics accessories: cables, adapters, earbuds and memory cards.
• Beauty accessories: lash kits, nail tools and brush sets.
• Toys and collectibles: action figures in contoured or multi-cell cavities.
• OTC and supplement lines: unit-dose cards sealed front to back.
• Automotive aftermarket: fuses, bulbs and sensors.

Mistakes to Avoid With Blister Cards

• Not confirming the peg: a Euro slot card on a round-peg fixture, or the reverse, gets pulled from the planogram.
• Trimming the card tight to the flange: it looks unfinished and leaves no room for the hang area or copy.
• Thin board under a heavy product: step up the caliper or double the header rather than hoping the hole holds.
• Artwork across the seal zone: type and barcodes under the flange read badly and lamination there blocks the bond.
• Ignoring grain: grain set the wrong way lets the card bow forward on the peg.
• Skipping the sample on a deep cavity: anything past about 1 in deep should be sealed and hung as a sample first.

MOQ, Proofing and Production

MOQ starts from 100 units on standard card sizes. A custom thermoformed cavity, trapped construction or multi-cell tooling raises the floor, and we confirm it at quote.

Send the product dimensions and weight, the card size you have in mind, the construction, the peg type and your quantity. We return a card dieline showing the cavity footprint, flange, seal zone and hang hole so artwork lands in the right place. Standard production runs 10–14 business days after artwork approval. Reorders on locked artwork may reduce proofing time because the structure and artwork are already approved, but standard production remains 10–14 business days after artwork approval unless otherwise confirmed.

Get a Quote

Related formats include custom retail boxes product page and custom hang tab boxes product page. Questions go to The Printing World at sales@theprintingworld.com or +1 (888) 883-6313.