You bring the tech pack and the yarn specification; the factory knits to it.
Send the tech pack, measurement chart and yarn specification
Agree the yarn quality and confirm the content in writing
Counter sample, then fit approval against your own chart
Wash test and measurement check before bulk is cut
Bulk production, inspection, packing and export documents
None of these five are published in the source catalogue. That is normal for a knitwear catalogue, and it is exactly why they belong in the first email rather than the last one.

70% Acrylic, 20% Nylon, 10% Angora
Autumn/Winter · View style
65% Viscose, 35% Rayon
All season · View style
Fibre content not stated
Spring/Summer · View style
80% Rayon, 20% Sequins
Spring/Summer · View styleLead times are not published in the source catalogue. Ask for the sampling lead time and the yarn lead time separately, because the second one usually sits outside the factory.
For development: a tech pack, a measurement chart with every point defined, the intended fibre content and the care label you plan to print. For catalogue selection: the item numbers and the quantity.
Put it in writing on both sides. A sealed counter sample plus a written tolerance is what makes a later inspection meaningful.
Sample cost and sample lead time are not published. Ask for both in the same message as the quotation request.
Send what you have: a tech pack, a chart, a photo or just a list of item numbers. The first reply will tell you what is missing.