Steve, this looks like a fun project. Why did you go with dye from Dharma Trading? Do you think the RIT dye commonly available at places like Walmart would work just as good?
No way. RIT is a multi purpose dye that is actually terrible for cotton. It will never truly be color fast, and will continue to fade indefinitely. The colors are also not as intense.
From everything I've read, RIT is pretty much only good for things like nylon. Which is exactly the opposite effect I'm going for. I don't want the thread or the patches to take the color.
The process I go through to dye the gi is simple, but there are multiple steps. First, I use a commercial detergent to wash the gi and remove any dirt, oils or finishes that could keep the dye from setting. I then use these Procion fiber reactive dyes. I also use salt to make the colors brighter, and something called calsolene oil. This helps prevent streaking and makes the color more even.
After that, I use soda ash as a fixative. This makes the dye permanent and colorfast, so it doesn't bleed. Then I wash it three times. First in the commercial detergent hot, then with my regular laundry soap plus white vinegar in the rinse, also in hot, then one more time in warm water with soap and a commercial fabric softener. Washing it three times gets 99% of the renegade dye out of the fabric.
Honestly, I believe that there aren't any shortcuts.
Edit: I just wanted to add, though, that it sounds expensive but really isn't. While there is an initial investment in supplies, most are good for multiple projects. It's about $10 per gi, which, if you figure for BJJ is about 6 lbs of fabric, is a pretty good deal. Lighter weight gis, such as are used in other styles, would be much less expensive.
