There are many acceptable ways to attach flatback rhinestones on a surface, but in my business, I only recommend two ways to attach it which is considered to hold the rhinestones stronger and make them harder to fall off.
The two recommendations from me are:
(1) Two-Part Epoxy Adhesive
The Two-Part Eopxy Adhesive provides a very rigid and durable bond for a wide range of surfaces like ceramic, leather, wood, metal, and many more materials. It is water resistant so it can be painted on top. It turns completely transparent after it is set, so it's suitable to use on Glasswares or transparent surface as well.
This kind of adhesive comes in a package with 2 tubes (A and B), also with a choice of "Quick setting" or "Slow setting". For rhinestones application, always choose the "Slow setting" ones. The extra long time on setting allows us to move the rhinestones to the right place before it's set.
Mixing: Please follow the instruction on the package for the mixing portion of tube A and tube B. Usually, the A and B should be mixed in 1:1 proportion.
Some brand which provides Two-Part Epoxy Adhesive:
(2) E-6000 adhesive
E-6000 is another adhesive which is commonly used for rhinestones application. It also provides a strong adhesion strength and versatility. The benefit of using E-6000 is no mixing is required, it can be used directly from the tube. The E-6000 sets quicker than the Two-part epoxy adhesive, it sets in 15 mins, then bond sets in 2 to 6 hours, and attain full strength after 24 hours.
However, the E-6000 adhesive is not recommended on some types of acrylic rhinestones, in which a clouding effect on the stones are reported.
For rhinestones adhesive supplies, please visit my Online Store at: http://www.qrhinestones.com
If you have any question, please leave me a message.