I believe you are talking about Unique Variants, in which case there are two ways to make them.
1. Craft something. Anything! There is a chance that you will gain a unique variant on the equipment you make (up to three variants). A lot of luck is required to get three variants, but sometimes you'll get at least one.
2. In the bazaar there are some crazy-looking gremlins (bottom-right of the Bazaar). One of these gremlins will apply unique variants to the equipment of your choice... for a price. If I remember correctly it is 20k for 1 UV, 75k for 2, and 225k for 3 (prices are in crowns). Still requires luck for the UVs you want, but at least it is guaranteed to gain UVs this way.
I believe you are talking about Unique Variants, in which case there are two ways to make them.
1. Craft something. Anything! There is a chance that you will gain a unique variant on the equipment you make (up to three variants). A lot of luck is required to get three variants, but sometimes you'll get at least one.
2. In the bazaar there are some crazy-looking gremlins (bottom-right of the Bazaar). One of these gremlins will apply unique variants to the equipment of your choice... for a price. If I remember correctly it is 20k for 1 UV, 75k for 2, and 225k for 3 (prices are in crowns). Still requires luck for the UVs you want, but at least it is guaranteed to gain UVs this way.
Hopefully that answers your question!