Hi Marius, welcome to the forum!
There was a discussion on oil size recently, browse through it, and you'll get a good idea of what others are using:
https://handletteringforum.com/forum ... f=2&t=3412
I've found OneShot Quick Size to be unreliable unless you have some old stock. Even at that, size one job and it'll be ready to go in an hour, other times two - three hours under the same temp and weather conditions.
I have some old Rolco and use that occasionally, and find it to be more reliable. Doug Bernhardt turned me on several years ago to Luna, available in 3,6 and 12 hour size, as a replacement to Le Franc when they dropped the lead from several of their products, and found it to be very reliable.
As for a 'glossy gold' with gelatin, it's used mainly for reverse glass work. Use of gelatin size on glass will produce a bright gold, whereas oil size will produce a matt gold. There is a 2 part, water based size available, for surface gilding that produced a very bright surface. I don't know if it's still available, so if anyone else could provide information, it would be helpful. The only problem I remember is that it's pricey, and has a very short shelf life.
The gelatin used frequently comes in sheets, scored into 'diamonds'. The gelatin sheets can be purchased at a grocery store that specializes in bakery goods, or online. Ratio is 4 diamonds to 16 ozs. of water, heat till dissolved but not boiled. I don't remember of using gelatin size for anything other than gold. Metal leaf requires a heaver tack that gelatin provides.
Danny
Well, I should have looked first. Check this out, Rick Glawson's information on size. Keep in mind this was written when 1 shot was reliable, as was LeFranc, unlike now:
http://www.theletterheads.com/glawson/goldsize.html
Also look over this - The Letterheads Site, a compilation of information and supplies:
http://www.theletterheads.com/index.html
You can also access the above link when you log in. After logging in, click on the tab at the top right - The Letterheads Site.
Lastly, in the frist link the two part size is mentioned that will give an extremely bright surface gild: INSTACOLL,
http://www.noris-blattgold.de/English/p ... 25317.html
The problem with any surface gilded project that will be in easy reach, or handled, the gold should be clear coated, which in turn diminishes the beauty of the gold itself.