After receiving numerous requests for an apparel primer, this is the beginning of a dialog. Please ask questions and share thoughts(:
What do you want to make? A shirt? Hat? Pants?
What kind of materials will be used? Is the fabric you desire available in an appropriate color? If not, what are sample minimums like? Production? Can you find the right fabric and piece dye it?
Will your run be large enough that minimums aren't an issue? Did you know that, with a minimum order, mills will make your fabric to order just like a machine shop makes parts? Do you want a blend of this and that, four way stretch, textured, tan 499, with antimicrobial treatment? No problem.
Does it need to be designed to be made using existing machines? Are you ready to invest in a few specialized machines to make life easier and be (more) profitable? If you've not yet invested in apparel machinery, now is the time to save significant money both in design and manufacturing.
Application? What is it supposed to do? How is it supposed to do it? Is it already out there? Can you do it better, cheaper, and/or sexier?
What kind of crotch? Fly? Waist? Inseam? Hem? Pockets? Buttons? Zippers? and loop?
What kind of collar? Sleeves? Torso? Hood? Cuffs? Pockets? Buttons? Zippers? Hook and loop?
What kind of brim? Fit? Floppy? Rigid? Sun? Rain?
Sizing? Fitted? Athletich? Baggy? Relaxed?
Four way stretch? Woven? Knit? Ripstop? Windproof/waterproof?
Gusseted crotch, gusseted armpit, flat felled seam, overlock, way stretch, woven, knit, straight or keyhole buttonhole,
For the sake of this discussion, a pattern is not a rigid template which may be traced on fabric. A pattern, in this instance, is the CAD file(s) and accompanying TDP, BOM, and/or assembly video(s) necessary to manufacture a sewn item.
Upon completion of an apparel project, you should have an industry standard pattern (Accumark, our preference, or Optitex) file, sample garment(s), and an estimated production cost. If you're running a nonproprietary cutting machine, request exported DXFs.
A simpler raglan, combat style shirt can run $500ish to have the pattern made. Sample garments and grading will be additional. After samples and revision(s), expect to spend up to $1500.
Pants with pockets and technical features can easily range from $1000-$2500 after samples and revisions.
A sophisticated jacket or smock with liner, pockets, a hood, etc can quickly approach $3000 after samples and revisions.
While this can be an expensive process, remember that this is a small cost when making thousands of garments in a production run. Short run clothing can still be profitable but your apparel must be well executed in order to charge the money necessary to be profitable. Is your concept really viable? Do you have a novel and practical idea or do you with to simply have your own branded clothing line? If that's the case, there are many more cost effective options to exploit existing OEM manufacturing options.
Familiarize yourself with apparel and assembly processes. Purchase apparel sewing patterns from your local arts and crafts store, Amazon, etc and a home lockstitch and overlock machine. Start making clothes.
Purchase patternmaking software or find a talented patternmaker. Accumark and Optitex can run up to $10k for a single seat. You'll also need a plotter, knife cutter (Eastman, Gerber, Lectra, Dema, etc), or laser cutter to cut the material. Contracting a talented patternmaker is almost always more cost effective.
Stop thinking BDU or ACU style clothing. Surface mounted, welted, etc style pockets require automated folding and mounting machinery that is the opposite of cheap. Again, were one making a gazillion parts, it's just a cost of tooling up for a production run. When you're talking 10s of parts, more efficient designs and manufacturing methods must be used to make a pair of pants that may be retailed at a price that won't cause sticker shock. Panels, seams, and top stitching, while more labor intensive, are much more practical for short run. Panels and seams offer all sorts of cool opportunities to mount a tab, loop, or whatever else. By rolling pockets, features, etc into seams and integrating modular design features, a cleaner part with minimal snag points is possible while providing some configuration options.
Zippers and hook and loop aren't necessarily the first choice but they're cheap and easy to integrate into clothing. Choosing the right zipper can minimize failures. Mount loop on the appropriate surface to facilitate user serviceability. Who wants to figure out the user serviceable, field repairable, modular, gated zipper system? It would be totally sweet. Buttons, snaps, etc require costly, dedicated tooling to mount in an efficient manner.
Will you make sized clothing, BDU sizing, one size fits most apparel? Sizing and odd colors result in dead stock and will kill your apparel profit margin. 90% of men's clothing we sold was medium and large. For women's it was almost all extra small and small. It's a nice thought to make sizes for everyone but the volume, for most manufacturers, is not there to justify gambling on dead stock. For your first run, stick with sizes and colors that will sell. If, after you've run all the numbers, you made money on your first run, kudos to you. Start planning your next run and consider adding more sizes.