I'm only partially kidding there. ^_^;  I have 
two cels I've framed myself, and I don't know if 
I did something wrong or not, but they do strange 
things when it gets hot or humid out. . . They 
warp in weird ways that make me worry if they're 
about to get damaged. o_0;;

But if you still want to frame your cel, it 
sounds like you're definitely on the right track. 
^_^  You want to use all acid free material. You 
will also need a *VERY* deep frame. (My two are 
each about an inch and a half deep.) If you would 
like a mat, I know that a chain store called 
Corners carries pre-cut mats of various sizes and 
colors at very cheap prices. (Although the mat 
size you'll want for a standard sized cel will 
most likely be 11x14 and those are usually sort 
of picked over - it's a popular size.) You might 
want to check if there's one near you.

Also, one thing I did to perk up the two cels I 
framed (which don't have backgrounds) was to buy 
acid free colored paper (only about $3 per 100 
sheet pack at a local craft supply store). I 
found some sheets of a nice almost neutral tone 
that went with the major colors of the cel. ^_^ 
Look for the paper in the section where they keep 
material for making scrapbooks.

Last, the thing I like the most about the way I 
framed my cels is that I put a spacer inbetween 
the cel and the back piece of acid-free foam 
core. This raises the cel off the "background" 
and you get a little 3-D type of effect. It's 
very asthetically pleasing, even if it does draw 
attention to the warping on hot days. ~_~

Somewhere on the Forum, I put up a picture of my 
framed cel of Clary right when I was done framing 
it. Do an "author" search for my name and you can 
see how it came out. (You might have to go back 
one archive instead of looking in the current 
one.)

Seriously, though. . . I am considering removing 
my two framed cels from the frames because of 
this warping that I've seen. . . So think about 
that before framing.

Many Sharp Smiles,
--Drac