"The original picture actually used in the work 
is used, and a skillful craftsman paints one 
sheet at a time by handmade business." 
Amikai translation  cel 
main page

"Although the transfer method of a carbon copy is 
used at the time of TV televising, the main line 
will be faded by long-term preservation if it is 
this method. By duplicate cell drawing, the 
optical sticking-by-pressure method is used so 
that degradation cannot take place easily." From 
the Making Of page, translated again by amikai.

Apparently it's a higher-quality xerox of the 
lines, hand painted, and includes a frame of the 
cel, and a certificate.

---Fireye