Specification

Clear PVC and TPU windows on a cosmetic pouch: three numbers to specify

25 Oct 2026

Answer first: three numbers decide whether a clear window reads as premium or arrives cracked — the thickness of the sheet, how the panel is attached, and the cold-crack rating of that sheet. Everything else about the window is decoration.

1. Thickness

0.3 mm is the common window weight for a pouch. Go to 0.4 mm when the window is large, when the bag folds across it, or when the window is the front face rather than an inset. Thinner sheet wrinkles along the seam and the wrinkle stays — it does not relax with use.

2. How it is attached

Two options, and they fail differently:

• Stitched. The needle perforates the film, and every hole is where a tear starts. It needs a seam allowance wide enough to carry the stitching, a corner radius instead of a square corner, and tape or binding over the seam so the film is not pulled at a bare edge.
• Welded. Cleaner and stronger, but it only works when the substrate behind the window is compatible with the film. A weld onto a coated canvas or a silicone-treated surface will not hold.

Whichever way it goes, put the radius on the drawing. A 90-degree corner on a clear panel is a tear waiting for a cold day.

3. Cold crack and plasticiser

PVC and TPU have a temperature below which they crack when flexed. Ask the sheet supplier for that figure for the exact sheet, and compare it with the coldest point on the shipping route, not with the temperature in your office. A window that is fine in June can arrive split in a January container.

On plasticiser: PVC contains it, some markets restrict specific phthalates in consumer goods, and the buyer’s compliance team decides which rule applies to their product. We do not print a regulatory status on a page unless the sheet supplier’s declaration covers the lot in hand — so if the window is going into a regulated market, say so at enquiry and it becomes a material question, not a decoration question.

What to put on the drawing

Sheet thickness, attachment method, corner radius, whether the window is flush or inset, and the tolerance on its position. Five lines that remove most of the back-and-forth.

Orders start at 3,000 pcs, or 1,000 pcs per colour or size on stocked materials. Send the drawing, the market and the shipping month and we will come back with the sheet we would use and why.