Anybody know a non toxic paint or markers that u could draw temporary tattoos with?

you know those stickers they sell at the tanning salon? well where else can i buy them? and is there a difference between both of them or can i just use normal one's?

I just got a really nice henna and i dont want it to fade, but i swim a lot and i can't really do anything about that.. so how can i preserve it so it will fade slower? i hear that vaseline protects it during swimming but also i heard it makes it fade quicker... help?