We looked for each of these specifically rather than assuming. Where we found nothing, that is a finding, not a gap in the research — and it is worth knowing before you plan a project around it.
A dedicated yarn shop
Oʻahu has had no local yarn shop since Yarnstory and Isle Knit closed. Wool, alpaca, indie-dyed, sock and weaving yarn, spinning fibre, looms and wheels are all mail-order.
What people do instead. Craft-store acrylic at Ben Franklin, yarn among the fabric at DeStash Hawaii, eyelash and sparkle yarn by the pack at Max Imports, and needlepoint and embroidery fibre at Needlepoint, etc.
Stained glass supplies
No retail source on the island for sheet glass, lead came, copper foil, flux or soldering supplies. The businesses that surface in searches are makers and commission studios, not suppliers.
What people do instead. Mail order. Note that Glass Fusion Collective covers fusing glass only and explicitly will not fire stained or window glass — the two are not interchangeable.
Leathercraft supplies
No verified source for hides, edge tools, stamps, punches or hardware. There is no Tandy Leather in Hawaii.
What people do instead. Leather is not hazmat, so it posts fine — the cost is freight and time, not restriction. Hawaii Sewing Supplies covers some of the hardware and heavy thread side. For learning rather than buying, Open Sea Leather runs bag-making workshops on Nuuanu Avenue.
Lampworking
No source found for rods, torches, mandrels or lampworking kilns.
What people do instead. Mail order, with the usual restrictions on anything pressurised or flammable.
Soap and candle making at any scale
No dedicated supplier. Lye is corrosive and classed as hazmat, so it is caught in both traps at once — arguably the hardest craft to start here.
What people do instead. Ben Franklin and Daiso cover melt-and-pour bases, wax, wicks and moulds for small batches. Beyond that you are looking at freight, and lye may not be shippable at all.
Kapa materials
Wauke bast, iʻe kuku beaters and dyes are not sold retail on Oʻahu. This knowledge and these materials pass through practitioners and cultural organisations, not shops.
What people do instead. The route in is a class or a practitioner, not a purchase.
Michaels and Hobby Lobby
Neither chain has a store anywhere in Hawaii. Hobby Lobby’s own directory lists 48 states and Hawaiʻi is not one of them; Michaels’ own state list jumps from Georgia to Iowa.
What people do instead. Ben Franklin Crafts is the equivalent, and it is locally owned.
Anything at all in West Oʻahu
No craft store, no art supply shop and no fabric shop verified west of Pearl City and ʻAiea. Pearl City is the westernmost Ben Franklin.
What people do instead. Kapolei has the Habitat ReStore and Honsador. Everything else is a drive into town.