Material selection

Structured or soft: what 1.2 mm PU does to a pattern

26 Oct 2026

Answer first: the premium look of a cosmetic bag is stiffness, and stiffness is bought in the material and then paid for in the pattern. Moving from a 0.7 mm to a 1.2 mm shell does not just make the bag firmer — it changes skiving, seam allowance, edge treatment and whether the base needs board.

The soft end

PU leather, smooth matte, 0.7 mm drapes, folds and packs flat. It is the sensible choice for a pouch that goes inside a gift box or a travel bag, because it takes the shape of what is around it. Three consequences: it needs interfacing to hold a straight edge, every crease it takes stays, and it will not stand up in a shop.

The structured end

PU leather, structured grain, 1.2 mm holds a shape with nothing inside. What changes on the drawing:

• Corners need skiving. At that thickness the seam allowance has to be thinned at the corner or the corner will not turn cleanly and the bag will not sit flat.
• Seam allowance is thicker, so the finished size grows. A panel cut to the same dimensions as a soft version comes back bigger at every seam.
• Small pouches start to look bulky. Below roughly the size of a hand, a heavy shell reads as a box rather than a pouch.
• The base needs board. A structured shell will sag in the middle of a large panel unless a PE board, 1.2 mm carries it — and the board must stop short of the seam, or it wears through from the inside.

What “premium” is actually made of

Not thickness on its own. The signals a buyer reads in the hand are:

• Seams that stay straight over a curve.
• An edge that is finished, not just turned — a piped edge, which is why the rounded pouch with a piped edge reads more expensive than a plain one of the same material.
• Hardware with weight. A polished metal #3 zip changes how the opening feels before the customer has looked at anything else.
• A lining with body — satin at 210T slides, velvet grips, and the difference is felt in the first second.
• The same stitch length on every seam, visible from a metre away.

The one material to think twice about

Metallic film PU at 0.8 mm is the most photographed finish and the least forgiving: the film shows every scratch and every fold line, and a corner that is skived badly shows as a bright line. Use it on panels with few folds, or expect returns from the second month of use.

How to decide

Decide the shelf behaviour first — does it stand, or does it lie in a box? — then pick the shell to match, then let us adjust the pattern around that choice. Sampling runs about 7 working days per round, and the first round is where thickness gets settled. Orders start at 3,000 pcs, or 1,000 pcs per colour or size on stocked materials. Send the drawing and say where the bag will be sold.