Different techniques can be used to achieve different effects on silk. Most of these techniques can be used with various brands of paints/dyes. Some brands may carry their own products to achieve specific techniques. Also, depending on the paint/dye you are using, the fixing methods could be different, but you still can use all the techniques.
Once you have your silk painting fixed you can paint again on top of it with a different technique (i.e. you can use gutta technique, fix it, then use antifusant/salt/wax/... and fix it again). And some techniques can be applied at the same time on the same silk painting as well (i.e. you can use wax and gutta on the same painting).
Different products are available all around the world, but here are some of the techniques to use.
Serti technique (gutta or any other resist).