I think that type of varnish there is just for paintings, not for prints! You could try it though - it might work the same - just follow the instructions on the bottle. I don't think that it is for prints though - I don't think it's a "heat set" either, so you might not want to bake it unless it says to, lol.
Oh yes!!! The type of giclee gloss I use is actually BACK in stock now though at MisterArt here:http://www.misterart.com/store/view.cfm?store=001&group_id=8416
they just got more in yesterday =) I'd say definitely buy some if you can! Just follow the instructions on the bottle. Here's the order to do things in (with the Genesis Giclee Heat-Set Gloss):
#1 Print the print
#2 Let the print dry for about 10 minutes
#3 Then, if you want to hand-paint some embellishments - for example, I paint over and add small details, and I sign & number the prints in paint (on my canvas prints in Photoshop before I print them I "erase" my old signature and date, so I can paint it on again specially). Hand-painting is the hardest step! You will need to use the paint straight from the bottle - with NO WATER on the brush or in the paint - otherwise, the ink will lift off - it's kind of hard!
#4 Then get a new brush (I have a brush that I ONLY use for the gloss - it will be ruined if there is any old paint on it, and once you've used it once for gloss, you can't paint with it normally since it will be shiny no matter how many times you wash it!).
#5 With even strokes, cover the WHOLE print with the giclee gloss!
#6 Put on a cookie sheet
#7 Bake in the oven at 265 for exactly 2 and a half minutes (in my oven at least - you might want to test it first since all ovens are different - it should be between 2 and 3 minutes).
#8 Take it out and let it cool off (about 20 minutes)
Hope that helps!!! >^__^