By the way, if you’re looking for someone to provide production sewing services — an industrial sewing factory — you are looking for a business known as a sewing contractor. If you have not used the term “sewing contractor” in your search, you will have found very little information that can help you.
To learn the correct industry terms and definitions you need to know, see “Job Descriptions in the Industry” in chapter 2 of The Entrepreneur’s Guide to Sewn Product Manufacturing.
Similarly, you’ll need to find more than sewing supplies, wholesale fabric or sales representatives. You’ll need to hire businesses you probably don’t even know exist; businesses that provide services such as pattern making, pattern grading, large-scale fabric cutting, makers of buttons, thread, zippers and elastic. You may also need a laundry service, a shipper and even, someone to lend you money!
But what you need first and most of all is EDUCATION because you’ll never find someone to teach you about industrial sewing (or industrial sewing methods) unless you know where and how to look.