I have a questions for you fantastically creative individuals:
How easy would it be to print a morale patch? (For those unsure of what a morale patch is http://milspecmonkey.com/morale-page/morale-patches Link may contain NSFW language or images.)
Typically they are embroidered but PVC ones are coming out now. I understand that printing with PVC can be hazardous to ones health, so what alternative materials could be used? (Bear in mind that they need to remain somewhat flexible.)
What would be a good way of attaching hook and loop tape to the back?
What printer would you recommend?
Thanks for your answers.
Some of the simpler ones (no fine details, less than 4 colors) wouldn’t be that hard to do by pausing and swapping out filament and designing the 3D print so that each color is on a different Z height in the print.
Nylon can be used to create a flexible badge - it’s not so much the printer (pretty much all plastic extrusion-based printers can achieve the same quality), but you just need the proper hot-end to be able to extrude Nylon. Triffid_Hunter apparently has been printing Nylon at 220C simply with a J-head hot end, while others have required much higher temps and all-metal hot ends. http://www.taulman3d.com sells the nylon filament, and it’s safe to use. Benefit is also that it only comes in 1 color, white. But it can be dyed with boiling water and simple fabric dye. However, this stuff is extremely “alpha” right now. AFAIK it’s nowhere near the friendliness of PLA.
http://www.3dprinterfilaments.com also sells some sort of flexible filament, but very little detail is available on what it’s made out of, how they managed to get it that way, its properties on a printer, methods of printing it, etc.
If the idea is to make one-off’s, you can print with nylon - Taulman has 3D printing nylon in white and red available now. Supposedy, the nylon can be dyed for color.
If the idea is to do short runs, and if you can use, say, rubber, it might be possible to mold your patches using 3d printed molds.
wouldn’t be a embroidery machine be the better fit for this?
Well, yes, naturally. 
@Andreas_Gohr Yes, for the traditional method, but as I mentioned, PVC patches are starting to become the norm. Besides, if I went down that route, I wouldn’t end up with a 3D printer. 
@Joseph_Chiu The idea would be a sort of print on demand style business, selling my own designs (and those of others if they can’t get them manufactured).
@ThantiK Thanks for the informative post.