1:3, G-Gel:cwm is an ideal proportion for maintaining the cwm’s matte finish, texturability and thickness. You can add as much 1:3 G-Gel/cwm as you want to a paint mixture AS LONG AS THERE IS A LITTLE PAINT in the mix! The G-Gel makes the cwm stronger, more flexibile (cwm on its own dries without any of the flexibility that oil and alkyds have).
You can use as much as 9:1 G-Gel/cwm to oil colors, BUT then do this throughout the entire painting – keep each layer consistent – don’t mix things up with regard to proportions of G-Gel:cwm when adding to oils because then you are messing with the fat (flexible) over lean (inflexible – no fat) issue. By increasing the amount of G-Gel to cwm, you’re getting higher and higher gloss as well, and if you switch to less G-gel concentration, you’re trying to put something more matte and leaner over something more glossy and fat – WHICH IS NOT GOOD structurally.