I just used this method. I bought the sample size (7.25 oz) of Behr brand, "barn red" from Home Depot for about $4. I thinned it out about 1:1. This way it was plenty to do one girth belt, plus thinning it out helps it soak into the fibers a lot better. Hung it out to dry and it looks great. Thanks whistle8mp.
So after trying to die my girth I finally lost it and went down to my neighborhood paint store. I brought a color so they could match it correctly and bought a LATEX stain to die it with. It worked amazing and its so much easier and it does'nt rub off on your flightsuit. So heres what I did
First I get my paint roller liner, stain and girth ready to die.
Then I pour the stain in the liner and begin to soak the girth untill its obsorbed enough stain so theres no white showing. Make sure you force it in with your fingers and hands.
Then once you have it soaked with stain your gona want to ring out the excess stain so it can dry quicker.
Your going to want to hang it up so it can dry but while its hanging get a rag and blot out as much excess stain as you can. Make sure you don't rub it or it will fray, only blot it. Then when thats done just let it air dry for about 24 to 48 hours and your all set. The key thing is to only get latex stain because all other stains will eat and corrode your girth. A pint of stain costs about thirty bucks but it saves you all the headaches that come along with dyes. A pint will dye two girths so if your doing more then that I suggest to buy a gallon. I have only done this in ROTJ color but they can match any color you like.
My waist is 38" but I bought th 42" natural from Amazon and it fit with just a little gap.
I tried Rit dye (chocolate brown) twice and it barely turned pink.
Then I found some stuff at Walmart called "Rit Dye More"- specifically for synthetic material.
Followed the directions and it was dark brown in 5 minutes. Worked fantastic. Only problem now is that boiling the belt in water made it shrink to a 32" belt!!!
I'm going to donate the shrunk one to wifey and try a 48" next time