The base rate of success is 67%.
To increase your success rate you can use a +3 or +4 Silver Embroidered Craftsman’s Clothing, a Sharp Alchemy Stone and the either the Pearl costume or a Couscous if you don’t have the costume. With these combined you should reach 100% success rate.
If you are using mastery clothing for mass proccessing, then you can use the pearl costume, verdure draught, seafood cron and a Sharp Alchemy Stone instead.