So after some extensive experimenting I think I figured why it only crafts fine quality items when using masterwork ingredients, basically the chance for fine quality becomes 100% and since it first check if the items will be fine quality it doesn't get to the check for excellent quality and in such manner doesn't check for masterwork quality, because when using excellent quality ingredients I only get fine quality items at are rate of 75 FQ : 25 EQ , so you get the same thing when using, well that is when I'm using 1 ingredient, when you start mixing ingredients of different quality it becomes more diverse but it still more or less follows the same rule where when chance for FQ exceeds 100% you only get FQ products, so when I use a combination between EQ ingredient and FQ ingredient I get something of the sort of 60 FQ : 24 EQ : 16 MWQ there is some randomness so I don't get an even distribution each time, don't know how exactly the code is written but I'm pretty sure that this is the reason you are unable to get MW items when using MWQ and EQ ingredients, using at least one fine quality item should yield the best results, when all ingredients are FQ the distribution is probably something like 12.5 NQ : 37.5 FQ : 25 EQ : 25 MWQ, so each ingredient above FQ in a recipe with multiple ingredients would reduce the chance of getting MW. Another interesting thing is that when combining a MWQ ingredient with NQ ingredient it seems you are unable to get NQ crafts but it similar to using EQ ingredients, except the distribution is something like 47.5 FQ : 47.5 EQ : 5 MWQ. Well those are made on a 6 spirit crafter and I tried to remove any food that buffs quality, so I have no idea how it is going to work if you use food or if you use a crafter with less spirit.