Paper Weight and Photo Safety

Paper is critical for many projects and unfortunately it is all too easily misunderstood. As an example, Creative Memories has changed its album page to what appears to be a more flexible, less stiff paper. Does this mean the paper is thinner and less durable? Not necessarily.

To measure paper weight, cut out a known area and weigh it. Divide the weight by the area. If the weight is in grams and the area in square meters, your answer will be in grams per square meter (gsm). I checked an old (October 10, 2005) and a relatively current (2013) album page. The old page came in at 212 gsm and the new one at 213 gsm. These two measurements are within experimental error and indicate that the paper weight has not changed.

I used metric measurements above, because English units for measuring paper are just plain confusing. However, we can use a measurement conversion tool to convert the metric unit to English pounds. Cover weight paper is traditionally used for album  pages. In this case, we find that the old album page had a cover weight of 78 lbs. and the new  album page had a cover weight of 79 lbs. These weights are slightly less than the probable specified cover weight of 80 lbs but within allowable tolerances.

The next question that comes up is whether or not the paper is safe for use with photos. Paper weight has no relationship to photo safety.

I really can’t help with photo safety since I now have no ability to complete the required tests. The four tests that are required are pH, buffering, lignin, and the Photographic Activity Test (PAT). Because paper manufacturing processes change over time, all tests should be run within the last year. pH should be alkaline with a value greater than 7.0, and buffering should be greater than 2.0 %. In addition,  paper should not contain lignin and should pass the PAT.

For colored paper, you will also want to add bleed to the list of required tests. Colored paper should not bleed. You can do this test yourself. Simply place the colored paper in contact with a piece of white paper. Paper clip the two pieces together and place in water for 24 hours. If the color paper bleeds onto the white paper, it is not photo safe.

For more about paper, see Pick the Perfect Paper.

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