My go to elastic guy is John TEX and TRIM 818 Wall ST Los Angeles.
Now if you look behind me you will see and 20 thousand pound pile of fabric- I am sure there are some gems in there, but it reminds me too much of my garage and that stresses me out
ahh one of the many aisles of trims, elastics, and stretch lace all neatly organized in NO WAY SHAPE OR FORM. Theres only one way to find what you need, and that is to ask. Hey, I need 2 inch black elastic BOOM. I need half fold black elastic DONE. Do you have this exact thing in say, purple? OF COURSE! And then its all neatly packed for you like this...
But, THIS little bag only cost me 14 bucks. 10 yards 3 inch white elastic, 10 yards 2 inch wide black, and 30 yards of misc elastic for my underwear making. Totally worth it.
I hit a few other places- and wound up with some solid black, white star and awesome polka dot fabric. Now this is some heavy duty stretch, super strong, thick weight- none of that "your skin is showing through your leggings" crap.
I have some ideas for these.... ill show ya when I am done. Haven't even got the pattern in the mail yet :)