A dark ink would work on lighter jean fabric. For the darker fabric, you might want a paint instead. For ink especially, you'd want to use some type of stop-flow product on the fabric first, so it doesn't spread out and get fuzzy. Check out dharmatrading.com -- they have all that stuff and can tell you the best things to use for your purpose. Have fun!

thank you.. I was wondering where the best place to purchase would be