Specification

Box pouch or flat pouch: the dimension your drawing forgot

25 Oct 2026

Answer first: a 2D drawing of a 3D bag is always missing one dimension, and it is almost always the base. That missing dimension is why a pouch comes back from sampling taller than the drawing, and why the zip is short when the bag is full.

Flat pouch, box pouch, and what sits between

A flat pouch is two panels sewn together. Its finished size is basically its cut size minus seam allowance, so a 2D drawing describes it completely.

A box pouch has a base and four sides — the drawing shows the front, and the depth is a number written in a corner, if it is written at all. That depth is added to the pattern, not shown on the drawing, and it changes three things:

• Finished height. A 200 mm front panel with a 60 mm base is a bag of 200 mm plus roughly half the base once filled — not 200 mm.
• Zip length. The zip has to span the top opening plus the base it folds over. A zip sized off the 2D drawing will not close on a full bag.
• Internal volume. The corners of the base eat into it, and piping eats more.

The questions that settle it in one exchange

Ask the buyer, in this order:

1. Is the size given flat and empty, or filled and standing?
2. What has to fit inside — longest item, widest item, tallest item?
3. Does the bag have to stand up on a shelf, or sit in a gift box?

Those three answers usually change the drawing more than any aesthetic decision will, and they are cheapest to ask before sampling rather than after.

Where the base goes wrong

Two recurring faults, both visible in the first sample:

• The boxed corner is too small for the depth. The bag looks right from the front and bulges at the base seam.
• The base has no stiffener. A structured look needs a PE board of about 1.2 mm in a sleeve under the lining; without it the base rolls up as soon as anything is put in.

Write the depth on the drawing

Front width, front height, base depth, plus which of the three is measured filled. That is the whole fix — and it lets the sample arrive the size you thought you ordered.

Orders start at 3,000 pcs, or 1,000 pcs per colour or size on stocked materials. Send the drawing and the contents list; if the base is missing we will tell you before quoting rather than after sampling.