What I Found At The Back Of The Cupboard

[Clockwerk]

A box of apparently unopened Gaf Gafmate Econoline S5 sheetfilm. I've tried googling it and nothing- I'm assuming the 'line' part means it's line film, but has anyone used it, is there anything I can do with it, or shall I just bin it?

 

[WolfTales]

Whats the expasperation date? Erm - I mean expiration date - ?

 

[Mike Wilde]

If it is line film it was a graphic oriented film, back before computer oriented printing layouts became the standard.

Graphics films were usually orthochromatic (process under red safelight) and slow - like EI25 under xenon, or 12 under tungsten etc. Figure it might now be slower, like test it for ei3 and see what you get. Treat it like photogrpahic paper and print to it in the darkroom with your enlarger. Develop by inspection in Dektol like developer as a start to see if it is all fogged or not. Sometiems if fogged, it is just at the edges or on the first sheet of a package, so do more than one to test.

You don't mention the size; graphic sheets film came anywhere from 4x5 to way big. If 4x5 it can be processed in a very dilute developer and visually to a low contrast index to allow you to make unsharp masks with black and white negs.

If it is larger it can be used to do enlarged positives, and then contact to an enlarged neg for alt process contact printing requirements.
If you are chemically adventurous it is possible to reversal process the enlarged pos to go striaght to an enlarged neg with one sheet of film.

A step wedge printed along side the image wil go a long way to help you understand the effctive speed, and th effects of varied development.

 

[Clockwerk]

Thanks for the info Mike. I'll check it out when I get back to the darkroom next week. It's bigger than 4x5, not as big as 10x8. I'll have a play around with a few sheets, see what gives.

 

[Mark Antony]

I'm not sure 'econoline' means it is line neg it could just stand for economy line?

 

[JBrunner]

I'm not sure 'econoline' means it is line neg it could just stand for economy line?

Although they are out of the film business, GAF is still in business. Maybe someone there remembers...

http://www.gaf.com/General/GAFintro_MAIN.asp

 

[jonogmun]

I found this patent abstract for GAF Gafmate:

...Physical and photographic characteristics of silver halide emulsions containing salts of multivalent metals are improved by adding synthetic water-insoluble terpolymers of acrylic esters, glycidyl acrylates and acrylamides as emulsion additives. The crosslinkable terpolymers are highly compatible with silver halide emulsions containing multivalent metal salts when an acrylamide is a polymer component at less than 15 wt% and an anionic sulfate surfactant of the formula ##STR1## where R.sub.5 is a straight or branch-chain alkyl group of C.sub.4 -C.sub.12, R.sub.6 is a straight of branch-chain alkyl group of C.sub.8 -C.sub.20, n is an integer of 8 to 40, and M.sup.+ is an ammonium ion or, a monovalent metal ion such as potassium, sodium or cesium, is the dispersing agent during emulsion polymerization.
...
The salts of multivalent metals which can be used to improve the photographic properties of gelatino silver halide emulsions are metal salts of cadmium, magnesium, zinc, rhodium, platium and iridium. Typical examples are cadmium chloride,cadmium nitrate, magnesium chloride, zinc nitrate, zinc chloride, and rhodium trichloride....

I have no idea what all this means, but it appears to be a specialized photographic emulsion.

Jon

 

[Clockwerk]

If it is line film it was a graphic oriented film, back before computer oriented printing layouts became the standard.

Graphics films were usually orthochromatic (process under red safelight) and slow - like EI25 under xenon, or 12 under tungsten etc. Figure it might now be slower, like test it for ei3 and see what you get. Treat it like photogrpahic paper and print to it in the darkroom with your enlarger. Develop by inspection in Dektol like developer as a start to see if it is all fogged or not. Sometiems if fogged, it is just at the edges or on the first sheet of a package, so do more than one to test.

You don't mention the size; graphic sheets film came anywhere from 4x5 to way big. If 4x5 it can be processed in a very dilute developer and visually to a low contrast index to allow you to make unsharp masks with black and white negs.

If it is larger it can be used to do enlarged positives, and then contact to an enlarged neg for alt process contact printing requirements.
If you are chemically adventurous it is possible to reversal process the enlarged pos to go striaght to an enlarged neg with one sheet of film.

A step wedge printed along side the image wil go a long way to help you understand the effctive speed, and th effects of varied development.

You were pretty much bang on the money, Mike. The film is 13x18cm (metric equivalent to 5x7), and I attempted using it like photographic paper, and processing it in Ilford Multigrade (the only developer to hand): I got a positive transparency from a 35mm neg, with just the edges of the film fogged.

Thanks again for the information.

 

[Mike Wilde]

Glad my 'wasted' nights of lith film experimenting, and buying up old graphic print process photo data books have paid off for someone else. I was down in the darkroom cleaning out old working print boxes (my wife had just cleaned out 4 years worth of course notes from book shelves in the spare room, so I felt compelled to move something on in exchange), and I came across a bunch of lith work that I did about 3-4 years ago. It lit the fire to get back into that. Plus if I do I will gain some spare space in my freezer that the boxes of lith film presently occupy.

Do think about using it in a camera (maybe pinhole) and then as a foothold to getting into cyanotyping. Alt process is loads of fun, and it isn't necesaarily darkroom work. Once I have the large neg, I coat paper one night, and then pull it out and print with it in the next few days. The last session was during a family board games night. Print times were between 30 and 60 minutes under my sub $100 home built UV source. Developement was tossing the print in a tray and leave the water stream run on it for a few minutes or longer.

 

[Clockwerk]

I think I might have a go at using some of it in my old plate camera, see what results I can get out of that.

 

[2F/2F]

Assuming it is litho film, it should still be good. Graphic arts film lasts forever. You can use it for enlarged positive transparencies, or for interpositives for contact printing using alt. processes. It is not bad for pinholin' either (though it is very slow and is not sensitive to red light). You can use a variety of developers. A+B for halftone results, paper or film developer in various dilutions, or David Soemarko's LC-1 for highly controllable continuous tone.