Film-Tech Forum ARCHIVE: Cueing B&W prints

This is topic Cueing B&W prints in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Steve Kraus (Member # 476) on 02-12-2004, 11:10 AM:

Why is it so difficult to apply Clint Phare cues to B&W prints? Granted the scriber may not be very sharp but works just fine on color stock yet will barely mark B&W. Is B&W stock different somehow or is every print routinely Scotchguard or otherwise coated. I may have to make a scriber to fit a Dremel tool! [Eek!]

Posted by Tim Reed (Member # 137) on 02-12-2004, 12:05 PM:

It was that way making chemical splices, too, Steve. You'd have to wet the emulsion before it would scrape.

Posted by John Pytlak (Member # 331) on 02-12-2004, 12:44 PM:

The emulsions used for B&W print films are very different than those used for color prints. In particular, the color films have couplers, coupler solvents, and dyes, which tend to make the film emulsion more pliable and less brittle than B&W, which is mostly just gelatin and grains of developed silver.

Posted by Christopher Seo (Member # 7) on 02-12-2004, 06:57 PM:

John, would this explain why B&W films tend to shed much more than color films? I did notice that Kodak's specs for current B&W polyester-base print film 2302 feature the antistatic backing layer and 'process-surviving backside lubricant'. I'm curious as to why a similar acetate-base film 5302 is also still being offered.

Kodak Print Films

Posted by John Pytlak (Member # 331) on 02-12-2004, 08:54 PM:

It has always been more important to properly lubricate (edgewax) B&W prints, per SMPTE Recommended Practice RP151. The Kodak H-24 processing specifications also specify proper print lubrication after processing. Kodak does have lubricants in both the color and B&W film formulations, but the lube cannot be at too high a level (will cause loose rolls), and some comes out during processing or film cleaning. So post-process lubrication greatly helps reduce projector abrasion of the print that causes scuffing and flaking from the edges and perforation area.

As I understand it, some in the archival community still prefer B&W triacetate print film (5302) so replacement sections can be cement-spliced. With color prints, a full-length replacement reel is often more cost-effective. The technology used for Kodak VISION Color Print Film was not easily translated to triacetate base, and the labs have all eliminated the rem-jet removal step in the print process that was required for triacetate prints having rem-jet.