How exactly does the game decide what patterns are available in the sewing machine?
I have items I wore once below level 10 and sold ages ago that are shown as available patterns, and other items that I've worn for a fair numbers of levels, are still in my inventory, but never show up as available patterns. I believe there's some correlation between item rarity (common/rare/epic) of both the original and target item, and possibly original source (drop/notes/diamonds), but I haven't figured it all out yet.
Could anyone help me / point to a guide I've missed?
Suggestion: a future feature that would get use from me would be when dropping an item into the sewing machine, a button appeared somewhere (maybe change one of the purple bars?) that for some cost in diamonds destroyed the item but unlocked the pattern for future use.