Here is a list for all of those interested in crafts or who'll be visiting this beautiful city any time soon.
NOTE: These are the stores I like, frequent, patronize etc... There is not one store on the list that I haven't been to, and also I'm sure there are plenty more, but this ones are close to each other and I simply like them.
1-
Den Haan & Wagenmaker - traditional fabrics for patchwork and quilting (this is where I learned quilting). A very beautiful place to visit.
2-
Birdblocks - modern and colorful fabrics, for patchwork, quilting, sewing projects
3-
De Afstap - yarns, threads and accessories for knitting and crochet
4-
De Posthumus Winkel - rubber stamps, inks, wax seals - a beautiful store
5-
Copenhaguen Kralen Beads - all beads and related tools for jewelry making
6-
Koud Kunstje - papier mache, polymer clay, decoupage, wooden crafts
7-
Knopenwinkel - Buttons in all shapes, sizes and colors, and even if you're not interested in buttons you should take a look at this store, even the store's front sign is beautiful.
8-
Hema - This is a chain store, and there is one in almost every corner, but my favorite is the one on Kalvertoren, Kalverstraat 212. I've found many really nice party and craft supplies here, don't miss it just because you see a bunch of clothes and kitchen supplies.
9-
Vlieger - The one store I'm mostly likely to be found in. A washi-tape and paper heaven.
10-
Penelope Craft - I usually go more to #3, because it is easier for me to get there, but this is a very pretty and well stocked with yarns store.
11-
Van Beek - It is an art supply store (there are many here), but it is the nicest one and the staff are really helpful, and I don't know why but I really like it in there!
12-
Jan de Grote - If you find yourself in the Albert Cuypmarket and you like crafting, sewing etc.. you must not miss the chance to go in here. Lots of cheap materials; zippers, ribbons, felt, buttons, lace, etc...
13-
A. Boeken - A bit like Jan de Grote, only smaller and much more organized. Lots of ribbons, and fabrics. They have the nicest business card.
14-
Weldraad - Is a very nice and well illuminated yarn store in the beautiful Haarlemmerdijk street. They carry many types of yarns for all budgets.
I hope you find it useful and that you like some or all of these stores,
Giova