Sized to be carried on something else
A keychain pouch is specified from the ring or clip as much as from the contents: the attachment point takes the whole load every time it swings, so it is reinforced differently from a seam that only holds the pouch closed. Confirm the attachment on a loaded sample, and state what it clips to so the hardware is sized for it.
How the zip performs in use
A zip contains contents properly and adds structure, which is why it is the closure specified wherever small items would otherwise escape. It is also the component most exposed to wear: the tape, the slider and the pull are three separate quality decisions, and a cheap zip undermines an otherwise good pouch faster than any other single part.
Run the zip repeatedly on a packed sample. Smoothness under load, and whether the slider wanders off the tape at the ends, are not visible in a photograph.
The fabric
Cotton canvas carries load and holds structure, and it is the best print surface here — silk screen for spot colours, heat transfer for multi-colour artwork. Fabric weight is specified from the heaviest expected contents rather than chosen by look.
