All you need is White Out, Paper Towel, Oil, handgun...
Make sure your firearm is unloaded and pointing in a safe direction!!!!
Follow steps 1-6
Estimated time 8 minutes... if that!
1) put a thin layer of White Out over the area you want white.
2) WAIT 10 MINUTES White Out must be completely dry (the hardest part)
3) put a few drops of oil on a paper towel sheet.
4) rub the White Out very lightly, DO NOT SCRUB!
5) use another sheet w/ oil and wipe off excess White Out-
6) enjoy your firearm
I hope someone finds this helpful if they decide to fill in their Glock... it lasts for a while and can be removed using any decent gun solvent and a small paperclip.