A few more string bag pattern comments, for the smaller (no 20 ch loops) version:
If you use Coats & Clark crochet nylon and a 3.0 mm hook, you will need two spools.
If you use Lilly Sugar & Cream cotton and a 3.0 mm hook, you will need 4 2oz. balls. (You need just over three, so for two bags of the same thread, buy seven.)
If you need to join threads, lay the threads parallel and crochet them together from the top of one loop to the top of the next, continuing from there with the new thread. This is a somewhat thick and obvious join versus weaving in ends, but it is stronger, to resist the force of pulling from a full bag.
Re: Final pattern, I think
If you use Coats & Clark crochet nylon and a 3.0 mm hook, you will need two spools.
If you use Lilly Sugar & Cream cotton and a 3.0 mm hook, you will need 4 2oz. balls. (You need just over three, so for two bags of the same thread, buy seven.)
If you need to join threads, lay the threads parallel and crochet them together from the top of one loop to the top of the next, continuing from there with the new thread. This is a somewhat thick and obvious join versus weaving in ends, but it is stronger, to resist the force of pulling from a full bag.