How can I identify unknown paper?

[J Rollinger]

I recently bought a trunk full of darkroom equipment and noticed that one of the paper safes are full. There is about 50 to 100 11x14 sheets in the black bag inside. Can i visually tell if its color, B&W or graded?

 

[Photo Engineer]

Color paper will be blue or magenta in color. IDK about any others.

PE

 

[semeuse]

If you're lucky, they left the data sheet inside the bag. Color from B&W is easy as PE indicated. And then RC from fiber is also pretty easy. But, I don't think you'd be able to tell VC from graded paper by visual inspection.

 

[Roger Thoms]

Seems like some testing is in order. PE has told you how to identify if the paper is color. If the paper turns out to be black and white why not try exposing some test strips to different variable contrast filtration and see if it responds. I'd pick a negative I was familiar with for the testing. Just my thoughts.

Roger

 

[Vaughn]

I thought a real photographer could tell by the taste -- the older papers with the cadimum are distinctively flavored...jk

 

[Mike Wilde]

I go thought this quite regularly with 'found' photo paper.

The easiest way is with a step wedge and dichroic enlarger. Print a step wedge, projected or contact for these purposes, with only all yellow dialled in. Count the steps between all white and all black.

Then repeat with only all magenta dialled in. Count the steps as above. They should be quite differnt if it is MG paper. All papers loose contrast with age; don't be surprosed if it was once really a MG that you are down to a range of 00 to 3 as it ages.

Some fixed grade paper has some contrast variation wto magenta, but it is marginal.

If the paper is MG, then start to step though 170Y - 135Y, 105Y, 70Y 35Y 15Y 0 15M 35M 70M 135M 170M if your filters run to 170 or so. Looking at the steps, and the relative placement of the first non white can let you figure out what filtration is now neededd to print the achievable contrasts with the paper you have. I regularlly do this with a series of 2x2.25" chips cut from a piece of 8x10. I write on the back the filtration and then batch develop them all at once once the initial exposure is fugured out to get the scale of the step wedge to be centred up.

Without a step wedge, the same testing can be done with less presicions with a broad scale 'normal ' negative, and also with fixed tint MG filters, either of the above or below the lens variety.

If the paper is Oriental/Seagull MG it will adjust almost all the full range though only yellow filtration.
Agfa, Ilford and Kodak MG paer need yellow though magenta for their full range.

High magenta exposures usually need twice as much exposure than other filter settings to make up for the high filter factor the deep magenta imposes.

 

[Ray Rogers]

If the paper is Oriental/Seagull MG it will adjust almost all the full range though only yellow filtration.
Agfa, Ilford and Kodak MG paer need yellow though magenta for their full range.

Sorry Mike, I didn't follow this.
What does
"adjust almost all the full range though only yellow filtration." mean?

Thanks,

Ray

 

[Mike Wilde]

Some old Seagull paper I have had land on me from 'old darkroom unused supplies', with unknown age runs currently as 00 contrast with about 130Y, and gets to almost 3 by 0Y, and perhaps to 3.5 with about 15M. After that, lay on all the Mfiltertion you want, and the paper does not get any contrastier.

With most other vendors MG paper the contrast will get softer with more yellow, and keep getting harder with the more magenta filtration you dial in. The older papers do loose contrast, so don't be surprised if you are pouring in 170M and you only get the equivalent of a #3 contrast with this filtration.