Regalrez is great
Regalrez crystals are great for making your own museum quality oil painting varnish. It's surprisingly easy to make. All you need are the Regalrez crystals, Tinuvin (UV stabilizer), and mineral spirits. Varnish, any kind, any brand has a shelf life, so I prefer to make my own batches two or three paintings ahead of time as I need it. That way, I don't worry about how long it's been on the shelf.
Regalrez is extraordinary. It's got a beautiful finish. It easy to remove if you need, and it's what they use at the National Portrait Gallery. If you prefer a less shiny finish, you can cut down the shine by mixing cold wax medium into the mix. I love it! I wouldn't use anything else.