Why is litho film so thin?

[James Drukeli]

i just purchased a pack of Arista Ortho Litho Film and couldn't help but notice how flimsy it is.

 

[David Lyga]

It might seem flimsy, but that 'thinness' guarantees two things: 1) that you must not overexpose, or you will get nothing but blocked highlights and 2) if you properly expose, you will get a level of resolution that will be comparable to none other. In summation: you don't get your cake and get to eat it too. - David Lyga

 

[glbeas]

The original use of litho film was in graphic arts for platemaking purposes. Some litho film, such as what copy was shot on was thicker and the non emulsion side had some texture to it to facilitate spotting to repair image defects and dust spots. Others like what you have was mainly for halftones and other fine line work and the thinness was an advantage when taping a halftone or other artwork into a clear window in the page film situated where the halftone image was desired. Anything very thick would lift the page film off the plate surface in spite of the vacuum applied in the plate contact frame and cause distortions and bleed problems with any nearby copy. Higher end printers would often use a separate overlay with the halftones to overcome this but back in the day newspapers would tape them in direct to save time. I would imagine the thin base of the Arista is a holdover from that era.

 

[James Drukeli]

Thanks for the replies! Slowly making progress but shooting this film is difficult.

 

[David Lyga]

Thanks for the replies! Slowly making progress but shooting this film is difficult.

But, when you get the hang of it and honor its restrictions, you will reap bounteously. Don't expect it to be 'forgiving': it is not Tri-X, after all. - David Lyga

 

[darkroommike]

4x5 isn't too bad. Back in thae day the Kodak stuff came on 4 mil and 7 mil Estar (as I recall). Also consider larger sheets were most often used in graphic arts vacuum easels.

 

[koraks]

It might seem flimsy, but that 'thinness' guarantees two things:

The thinness of the base does not have much to do with the thinness of the emulsion.

 

[DREW WILEY]

When used for highlight masking or similar multiple sheet applications, the thinness keeps things crisper (less diffusion). You also need to punch through less, if you're punching sheets together. A thinner film base is probably cheaper as well. The current Arista product also has a slight texture to facilitate draw under a vacuum blanket; but at the same time, it suppresses Newton Rings.

 

[schrollphoto]

The original use of litho film was in graphic arts for platemaking purposes. Some litho film, such as what copy was shot on was thicker and the non emulsion side had some texture to it to facilitate spotting to repair image defects and dust spots. Others like what you have was mainly for halftones and other fine line work and the thinness was an advantage when taping a halftone or other artwork into a clear window in the page film situated where the halftone image was desired. Anything very thick would lift the page film off the plate surface in spite of the vacuum applied in the plate contact frame and cause distortions and bleed problems with any nearby copy. Higher end printers would often use a separate overlay with the halftones to overcome this but back in the day newspapers would tape them in direct to save time. I would imagine the thin base of the Arista is a holdover from that era.

Right! Personally “stripped “ hundreds of halftones in my 30 years in the printing industry. Probably shot thousands that others stripped.