6: For precision-critical products — registered foil stamping, die-cut positions with tight color tolerances — impose smaller, so the paper distorts less and downstream registration is easier.

7: Place heavy-ink, registration-critical areas near the gripper edge; deep color at the tail tends to smear and is hard to register.

8: For products glued on an automatic die-cutter, leave a generous gripper margin so sheets align flush during gluing without affecting the die-cut position.

9: Watch grain requirements at imposition, especially for distortion-prone blister cards, mounted cards, game boards, and rigid boxes — generally long grain.

10: For mounted products, weigh the paper usage as a whole — whether to waste face stock or liner — because sheet dimensions rarely divide perfectly; check which loss is smaller.

11: In three-ply mounting, the middle and bottom sheets should be 3-5mm smaller than the face sheet for easier mounting; register the die-cut off the face sheet for accuracy, or the plies may stick together.

12: When imposing cards, decide whether they are handled singly, in pairs, or in multiples — it matters greatly for finishing.

13: When imposing cards for a corner-rounding machine, a shared single-knife layout is fine; for a corner-punching machine, never share cuts — leave at least 6mm between cards.

14: Do not use water-based lamination on gold or silver board — it dulls the product and kills the luster.

15: On multicolor presses, print gold or silver solids last, so the metallic ink is not scratched before it dries. Any type over them — including black — must be knocked out. Gold or silver graphics and text must not print over solids that come later in the ink sequence; knock those solids out and trap them instead.

16: For numbered products, watch the number's length and position, and run numbering as the final operation.

17: When ganging multiple-up plates, make the upper and lower images identical so that ink density stays consistent on press.

18: Spot colors tinted with white ink should print early in the sequence, so the white does not cover the colors ahead of it.

19: When making die-cutting formes, note the crease-line requirements (perforation, crease, perf-and-crease) — perforation pitch, crease width, and so on.

20: Glue flaps on cases and boxes generally go on the larger panel.

21: For wine and canned-food labels, also watch the paper's grain direction — it varies by mill and batch — to prevent curling and poor gluing.

22: Ink color shifts after lamination or varnishing.

23: A silver underlay gives the product a metallic sheen — printing yellow over silver approximates gold.

24: When reviewing artwork and proofs, always draw out the finished structure — for example, the die lines of the carton or box — for checking.

25: How correct imposition affects die-cutting

When die-cutting on a flatbed automatic die-cutter, box edges often come out rough, which inevitably mars the product's appearance to some degree.

The main reason: on a flatbed die-cutter, the knives along the gripper edge must be nicked in several places so the finished blanks can be pulled smoothly out of the machine — and those nicks show up as rough edges on the finished box.

The fix is to impose the sheet so the box's glue flap sits along the gripper edge wherever possible. With clever imposition, die-cut boxes come out clean and attractive.

For jobs of two-up or more, printers generally use one of two approaches. If the graphics between adjacent blanks can join seamlessly, use a shared-knife (one-cut) layout with no gap between them: it saves paper, saves die-making, and eases stripping after die-cutting — three wins at once. If the graphics cannot join seamlessly, or the two shapes rule out a shared cut, leave at least a 4mm knife allowance between blanks and give each at least 2mm of bleed.

For glue-mounted products, enlarge the gripper margin where possible, so no adhesive squeezes out to affect die-cut registration.

Smart, flexible imposition thus saves cost and spares the die-cutting stage from avoidable problems.

26: The four most common paper sizes:

(1) Standard sheet: 109.2cm long by 78.7cm wide

(2) Large sheet: 119.4cm long by 88.9cm wide

(3) Self-adhesive stock: 765cm long by 535cm wide

(4) Carbonless paper: available in both standard and large sheet sizes

27: The common imposition schemes are as follows:

(1) Single-sided: for pieces printed on one side only, such as posters — the front is printed and the back left blank.

(2) Double-sided (sheetwise): the familiar front-and-back layout, for pieces printed on both sides such as flyers, small posters, and cards.

(3) Work-and-turn: suited to magazines and books. Take a 16mo magazine cover with covers 1 through 4 to print: impose cover 1 beside cover 4 and cover 2 beside cover 3, then pair them head-to-head on one quarto sheet. Print one side, turn the sheet 180 degrees, and print the reverse with the same plate. Cut the sheet down the middle and you get two identical finished pieces.

(4) Work-and-tumble: print one side with a plate, then tumble the sheet to print the back, using the sheet's opposite long edge as the gripper edge. Colloquially called "flipping the hopper," it is rarely used today. Remember to leave gripper margins on both edges.

Cartons (also called hard paper cases) are the most widely used packaging products. By material they include corrugated boxes, single-ply paperboard boxes, and more, in every size and specification.

They typically serve as the wrapping or protective outer layer for goods, sized to fit the product. Cartons commonly carry markings such as Handle with Care, Keep Dry, This Side Up, Stacking Limit, Keep Away from Sunlight, Moisture-Proof, Quality Assured, Do Not Roll, Do Not Step On, Fire Hazard, Fragile, Protect the Environment, Keep Away from Heat, Foodstuff, and Odor-Sensitive — graphic or text reminders that protect the contents from harm.

As an indispensable part of modern logistics, packaging cartons carry the important duties of containing, protecting, and presenting products, so their physical performance indicators are the basis of quality assessment. Stable testing conditions ensure accurate, reliable data, and veteran engineers with years of carton-testing experience analyze packaging performance, providing impartial, scientific test data for carton suppliers and users alike. TTS (Yitong Testing) also provides supplier material screening, tender evaluation, and related services for many well-known companies.

Corrugated board is made by gluing fluted medium — corrugating paper formed into waves — between facing and lining paper. Depending on packaging needs, it can be produced as single-face board or as 3-, 5-, 7-, or 11-ply corrugated board.

Different flute profiles yield boards with different properties; even with identical face and liner papers, flute shape changes the board's performance. Four flute profiles are standard internationally: A, C, B, and E. A-flute board cushions best, with good resilience; C-flute is slightly behind A in cushioning but beats it in stiffness and impact resistance; B-flute's dense pitch gives a flat surface and high compression strength, well suited to printing; and thin, dense E-flute shows off its rigidity.

1. Holographic laser film