It's convention season, and I have a few cels 
that I would probably like to get signed if I get 
the opportunity.  But most of them have pretty 
large images that take up most of the cel space.

So rather than have guests of honor sign on top 
of the image, I was thinking about placing a 
blank cel sheet over each original cel and have 
the autograph placed on the blank cel (I hope 
that made sense...).

I have never tried this before and therefore I 
would really appreciate recommendations from as 
many people as possible as to:

[1] exactly what I should be looking for (cel 
material, type of product, etc.)

[2] where I can find this at the best price 
(either online or in the Southern California 
area)... keep in mind, I'm not planning to buy in 
bulk unless I have to.

[3] any other suggestions that you might have 
that could help me out.

Many and different opinions are welcome!

Thanks, I greatly appreciate your help on this!