Three commercial printing processes
Lithography (offset litho) is planographic — a flat plate where grease and water don't mix: the greasy image area takes ink, the damp non-image rejects it. Gravure (intaglio) holds ink in recessed cells on a cylinder, wiped by a doctor blade so paper lifts ink from the cells — very long runs only. Screen printing forces ink through a mesh with a squeegee, a stencil blocking the rest — thick ink on any surface. Choose by run size and surface.
Graphic and smart materials by job
Paper and card are graded by gsm — up to ~200 gsm is paper, heavier is card/board. Corrugated card is a fluted core between two liners, stiff and protective. Foam board is a foam core faced with card, light and flat for models. Styrofoam is extruded polystyrene carved into 3D models. Smart: polymorph softens in hot water (~60°C) then sets rigid; SMA returns to a remembered shape when heated; thermochromics change colour with temperature.
Permanent vs temporary joints
A permanent joint uses an adhesive — a glue flap bonded so it cannot reopen. A temporary joint holds without glue so the pack can open, flat-pack and reassemble: slot-and-tab, arrow-tab (barbs stop pull-back), tuck-in flap or locking flap (tongue into a slit). Permanent for a sealed product, temporary where it must open or ship flat. On foam use PVA — solvent cement, superglue and hot glue melt Styrofoam.
Drawn from real examiner reports.
Office printer named for a commercial run
Asked how a large quantity is printed commercially, candidates answer laser printer, inkjet or photocopier — office machines for one-offs — and score nothing. The expected processes are lithography (offset), gravure, flexography and screen printing, economic in large numbers. Name one of these when a run is large or commercial.
w23 P51/P52 QA3a · s23 P52 QA2b(i) · s22 A2b — commercial/quantity printing confused with office methods (laser, inkjet, photocopying); litho, flexography or screen expected.
Solvent or hot glue on Styrofoam
Asked for an adhesive to join Styrofoam or foam board, candidates name a solvent cement, superglue or hot-melt glue — all of which attack or melt the polystyrene foam. The answer is PVA (polyvinyl acetate), water-based, bonding the foam without dissolving it. The tell: solvent-based or hot → off foam; water-based PVA is foam-safe.
s23 P51 QB4b(i) · s23 P53 QB5b — the correct adhesive for Styrofoam/foam board is PVA; solvent cement, superglue and hot glue were wrongly given because they melt the foam.
Foam board scored and folded like card
Foam board does not fold like card. Candidates score and bend it (crushing the foam) or cut through all three layers (separating the pieces). The correct method is an angled V-cut: two angled cuts remove a wedge through the top card and foam core only, stopping at the bottom card, left as a hinge so the panel folds cleanly.
s23 P52 QB5b(i) — folding foam board needs an angled V-cut through the top layer and foam core only, not scored-and-folded like card or cut through all three layers.
Lithography and gravure mixed up
The two long-run presses confuse candidates. Lithography is planographic — a flat plate where the greasy image takes ink and the damp non-image rejects it. Gravure is intaglio — the image engraved as recessed cells in a cylinder, wiped by a doctor blade, paper lifting ink from the cells. Flat plate + grease/water = litho; recessed cells = gravure.
Gluing a pack that must reopen
When a carton must ship flat and be opened and reclosed, a glued (permanent) flap is wrong — it bonds shut and needs glue on the line. Use a temporary joint: a locking flap (tongue into a slit) or slot-and-tab that holds without glue, so the pack erects, closes and reopens by hand. Match the joint to sealed-vs-reopen.
Thermochromic changes with heat, not light
Two smart-material mix-ups. Thermochromic changes colour with temperature (thermo = heat). The material that changes colour with light is photochromic (self-tinting lenses). And SMA (shape memory alloy) changes shape when heated, not colour. So: temperature → colour = thermochromic, light → colour = photochromic, heat → shape = SMA.
Name the process/material and justify
Marks are won on the justification, not the label: tie the printing process to run size and surface, a material to a property needed (corrugated card for stiffness), and a joint to permanent-vs-temporary. Stay within any stated restriction.
Match printing to quantity and surface
Read WHO, HOW MANY and WHAT surface. Fabric, a T-shirt or a sign → screen printing (thick ink, many surfaces). A very long run of leaflets or cartons → offset litho or gravure. Match the process to the run size and surface, not to habit.
Keep the model foam-safe
In a modelling answer, protect the foam: join Styrofoam/foam board with PVA, never solvent cement, superglue or hot glue (they melt it), and fold foam board with an angled V-cut through the top two layers. A melting glue or scoring foam like card loses marks.
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