A private animator phoned me back upon my 
request. Result: Schleiper (in Brussels, or are 
there more?) has cel sheets. I'll check'em out 
2morrow.

Cel paint: he always goes to BRICO and gets latex 
paint, dilludes that with water...

Here we go, I found it^^

PS NEVER use poster color on cels... too risky 
for the paint to "float" a millimeter above the 
foil, making it look stainy. And once water gets 
on it, it's f*cked up. AND it crumbles off.