Cels were regarded by studios as industrial by-product and hazardous to keep in large volumes . Therefore, they were often discarded as waste. A selection were sold by their studio for peanuts, some were taken home by their animators (with or without the authorisation of their employers) and some were salvaged by cel collectors standing at the backdoor of studios waiting for the studio's garbage to be taken out. This makes it very hard to trace the provenance of a cel back to its creators and so a collector will have to rely on other ways to determine the authenticity of a cel. Below are some factors to take note of: 

 

• Physical Inspection: Cels were used in the production of animation and should show a condition that matches its purpose. Certain cels (especially those from earlier animes) show signs of aging (yellowing / clouding / paint cracking). Tape and staples may also have been used. Cels from certain studios that used cheaper ink (ahem, Toei) very often have line fading issues as well.

 

Comparing the frame to the screen: find the exact shot of the frame in the anime and compare whether all lines and colour match.

 

There are online programs that allow users to compare images. Do note however that images of the cel should be scanned (instead of photographed) for the program to run accurate comparisons. 

 

Studios have their own formulas to produce colours, especially recurring ones on a Cel that don't look "natural" on first glance should be handled with caution. 

 

• Frame: the image on the Cel usually covers a wider area than what is displayed on screen. If a Cel contains image that goes beyond what is seen on the screen, then there is a higher chance that the Cel is authentic. 

 

• Size: TV cels are mostly 9" x 10.5" inches in size. Certain studios are known to use Cels of a different size. Check the measurements of Cel against other Cels of the same studio, or even better, of the same anime. 

 

• Background / Sketches: whether the Cel also comes with its sketches and/or matching original backgrounds. It takes substantial time, effort and skill to produce these which are less likely to accompany a copy Cel. 

 

• Markers: check whether the frame number corresponds to the sequence in the animation. For example, if the Cel is A10, does it really match the 10th shot of a sequence? 

 

• Seller: buy from reputable sellers. There are a number of well established Cel stores in Japan. Collectors also rely on the expertise of (certain more experienced) auction houses. There are certain sellers on Yahoo! Japan that are known to sell fake cels, purport to sell a cel by stealing an image from a previous sale and/or fail to deliver. 

 

• Due diligence: checking what information is available online - whether the Cel has been sold before, when and where. Whether someone else already contains the same Cel in his/her collection. Whether another collector has a Cel from the same sequence and whether the production markers and frame positioning matches with the Cel in question. 

 

• Price: whether the asking price corresponds to sale prices on the market. 
   

Even after considering the above, there is still a risk of a Cel being inauthentic. If in doubt, it may be worthwhile to also speak to other collectors who are often happy to share their knowledge and experience.