The history of the animation cel – Page 2

An 1896 patent application for a wheel casting machine.

At this level triacetate has shown itself to be in with more than a good chance. Film Sales’ search for an animation-copy-suitable triacetate cel concentrated on a formulation that provided the highest softening point to withstand that temperature, and one whose production ensures the absolute minimum of residual solvent. Removal of casting solvent could never be 100% – but any significant amount (even the ‘norm’ for triacetate) would boil off in the fuser and create unworkable or unspeakable curl as one side of the film shrink-dried preferentially. At the same time the optical quality was developed to cater for features demanding six or even seven overlay working with a minimum of paint shade variations, finally producing a Cel that they felt just had to be called ‘Premier’ Triacetate!

The honour of ‘low’ temperature copiers, which now abound, is satisfied as far as manual Cel feed and copying is concerned – but Film Sales were well aware from the tens of millions of OHP polyester copy sheets that they source annually, that multiple feed is a vital element to get real productivity benefit. The same technique of release gluing the film to a sheet of carrier/separating paper as used for OHP transparencies has been applied to field sizes of Premier triacetate so that the cassette of the copier can be filled with Cel and left to its own devices to auto feed in the same way as paper. The carrier paper also offers a marginal additional benefit as it gives a slight extra heat-sink back-up to the triacetate that can be helpful in instances where copier temperature is at the borderline level for plain film.
The first showing of Premier Triacetate was at an invitation Exhibition at The Royal College of Arts in October 1991, which confirmed the need for such a material, and initiated numerous UK studio trials that are progressing through to full sequence takes.

In practice this means that from 1992 animators have a realistic alternative to tracing. The existing office or studio copier might well be OK, as long as it’s the right size for their Cel field, but tests would be needed to check its suitability, largely dependent upon the copier’s age and fuser working temperature.

It is ironic that the copying problem was first solved in the 1960s when Studios installed Xerox 1385 machines that were ‘fuser-less’. After outline copying the Cel was carefully taken away from the cold copier with toner powder lightly clinging on, to be solvent- fused at room temperature in ‘biscuit-box’ trays with trichloroethylene vapour to etch it into the film surface. Cooling fans, open windows or sneezes were de rigour, but somehow even long feature films overcame the eccentricities of the process and studio folk were blissfully unaware of the hazards of the solvent they were using and breathing. Progress in this instance halted production continuing, as, not only did the machines get hotter with integral heaters, but many came to suspect that the whole world was also heating up with those dreadful chloro¬things attacking our ozone layer.

So Film Sales progress could be said to turn the clock a full 30 year circle and open today’s generation of copiers again to the needs of the outlining animator who still wants to bypass tracing. But this time, with the Animation demand growing and the Animation World so globally nearby there is even stronger pressure to take advantage of any process that will reduce those relentlessly rising production costs.

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Printed in Animator Issue 29 (Spring 1992)