Ph Testing With Lineco Ph Testing Pen

A while back I purchased a Lineco pH testing pen and have been checking materials I obtain through purchases.

Album pages (not a large selection) - most have tested as acid free. I had purchased a collection on Steiner pages printed on super thin paper and was surprised these tested ok.

Dealer cards - Some of these have tested acidic.

Manila pages - the majority of these test acidic. These are usually cut down pages to fit in an envelope.

Glassines - I am not sure about these as the surface does not really wet but none exhibit a acid free result. I got the same result from Dennision and Prinz hinges.

Thank you for the input.
If you have any older album binders that are not useable, please consider testing the cardboard in the front/back cover and let us know your findings.
Don

The Lineco pen only tells you if it is lower pH than 7.0, which is neutral. That's very inexact.

Here's what University Products has to say:
"With a simple swipe of Lineco's pH testing Pen, you can determine whether the paper and board you are using is acidic. This easy, convenient method allows you to distinguish the difference between safe (neutral or alkaline) paper and board and acidic materials. Easy to use, simply draw a small line on the material you wish to test. The chlorophenol red indicator solution in the pen will turn purple on any paper with a pH of 6.8 and above. A clear or yellow color indicates the material is probably unsuitable for conservation purposes. Paper can be respectably long lived if is pH is as low as 6.0, especially if is well made and carefully used and stored. In order to last for centuries in today's polluted air, it must have an alkaline reserve and this usually means a pH of 7.0 or greater. Please note: unreliable results may occur on colored or coated papers"

The sentence in bold is my emphasis. What do you chemists out there have to say about something that is pH6.8, which is indeed acidic but to me only slightly so?

We've already heard on SCF that a test on current hinges came out with a pH of 5.8. That's really close to 6.0 by my book.

However, we must all be aware that much of the paper in our stamps is definitely not pH 7.0. When left out, they do tone/oxidize over time. Ground paper pulp that much stamp paper is made of breaks down under such conditions making acidic byproducts as it does. Look it up. What is their pH on average, then? angore, you can do us a favor by testing some used junk stamps from the first half of the 20th century as well as some later ones. Then test some mint ones, too. I'll bet they mostly test as acidic.

Now, how much is the important question. I wonder if it's not in the range of pH 6.0. or so. I do see brown hinges that are close to crumbling or have crumbled, likely oxidized, yet the stamp is visibly okay. Seeing stamps toned from hinges, even the decayed browned ones, is rarely if ever seen. With proper storage, as noted in the blurb above, pH 6.0 paper "can be respectably be long lived, etc.".

Proper storage is then the key.

Keep in mind that the pH scale is logarithmic. So, a pH of 6 is times more acidic than a pH of 7 and that a pH of 5 is 100 times more acidic than a pH of 6.

Paper conservation specs include EN ISO 9706 which considers paper with a pH of no less than 7.5 as being in compliance.

I agree that the Lineco pen is a cheap, fast, method for hobbyists to check Lineco monitor their paper materials. It is not meant to be a scientific tool. For anyone who wants to get more serious about measuring their paper and albums you can learn more here https://nvlpubs.nist.gov/nistpubs/j...p553_A1b.pdf

For me and if my album pages tested at pH of 6.8, I would record the findings and monitor it over time. If the pH continued to drift downward over a few years, I would then be concerned and look into mediation.

Mediation - Paper toning and deterioration from acids occurs from two sources, the paper itself and the surrounding atmosphere.

The lignin in some paper itself breaks down over time and makes the paper acid. 'Acid free' paper has had buffers added but note that these buffers get 'used up' over time. So an 'acid free' paper in 2022 could be becoming acidic a few years down the road if the buffers get consumed. This is a good reason to test and monitor the paper pH.

The atmospheric conditions in and around your home may change over time. If your area has acid rain then it is possible that the atmosphere in your house could support paper to absorb the acids over time. Adding a wood burning stove or moving your collection to a wall which borders your garage could also introduce increased acids in your local air. This is also a good reason to test and monitor the paper pH.

Monitoring pH is the key since it tells you if you have proper storage or not AND gives you information on what is actually happening to your paper.
Don

Yes, I know the scale is logarithmic. Straight Coca-Cola is reported to be somewhere between pH 2 and 3, from 10,000 to a 10,000 times more acidic than pH 6. The difference between pH 6 and 7 pales by comparison. What is the difference between average stamp lifetimes in conditions between pH 6, 7 and 7.5? And do conservation specs include the first thing done to actively conserve documents, washing in distilled water?

Album pages, I get. But you keep dodging the fact that most stamps are made of wood pulp, too, and have likely degraded by themselves over time to greatly varying degrees. Active stamp conservation is a relatively recent thing.

Do you test your stamps, too?

I do not understand what the pH of Coke Cola has to do with this topic. The pH of our stomach is 1.5 to. 2.5 so Coke is not an issue unless you are eating your stamps.

It is true, as I have previously posted several times, that stamps (like all paper) will eventually turn to dust. I do not test my stamps nor is that the point.

In my opinion this hobby has largely ignored a lot of conservation issues; probably because it is easier and cheaper just to say, 'screw it, let the next guy deal with it'. The advent of 'print your own' pages in the hobby enabled 'thrifty' collectors to buy cheap 'acid free' paper from Big Box stores. Even legacy page/album manufacturers really do not promote the archival quality of their paper/products. Increasing education on conservation seems to me to be a good idea, I think the effort should be toward
A. An educational awareness
B. 'Do no harm' as hobbyists
C. Conserve with the objective to slow deterioration as much as possible

Monitoring and testing the stamps and covers in our temporary possession seems the responsible thing to do and promote.
Don

Latest ph test

Harris album page - tested ok (purple), The large X in center,

It has had a rough life. The pages had been cut down and repunched to 3 ring binder.

Hybrasil is correct. Most of the tests we can procure only indicate "acidic (7.0 and below on the pH scale) or basic (7.0 and higher on the pH scale). The Ph range is from 1.0 (extremely acidic) to 14 (extremely basic/alkaline). Both of those extremes would dissolve a stamp-and your skin too. So when most sellers of paper and pH tests use the terminology "acid free" they are simply stating the the pH is 7.0 or more. If you tested 1000's of papers you could get pH ranges in levels from 6.0 - 7.01 or so. But remember the range is only from 0-14 which can be easily determined by lab tests to decimal levels of hundredths. So, I digress and talk too much. But the point is that the "acid free" designation is scientifically incorrect and may not be a valuable indicator for paper that is safe to mount your stamps on. Lastly, my expertise comes from medical knowledge and definitely not from philatelic expertise. So, we still have a conundrum.

These pages were toned and did an acid check that I purchased second hand. It failed. It is more obvious around the edges. All the stamps are in mounts so will migrate but not pristine (future postage)/ The page is wavy due to too much moisture used on mounts,

I do not think there is any 'conundrum'. The inexpensive Lineco pen is indeed a 'go/no go' type of reagent and does not indicate the exact pH of the paper. But it certainly delivers more knowledge to hobbyists and is far better than not caring or not testing.

And while the entire pH scale goes from 0-14; pHs above 9 or below 3 are considered 'extreme' and few of us would ever find anything in those ranges during our lifetimes. Note that The pH of paper ranges only from 4.5 to 8.3.

Additionally there are other test kits and methods for testing the exact pH of the paper in our collections. For example, there is Micro Essential Labs Hydrion Insta-Chek 0-13 Mechanical pH Pencil for $15.00
https://www.amazon.com/Essential-Hy...70JPJK&psc=1

There are also higher end surface testing products but some can set you back $50-$75 or more.

I'd be happy if folks at would at least check what they are using to mount their stamps in and around. I have seen endless posts in this community which say something like 'oh, I purchased acid-free paper at Staples' but they have no actual idea if their stamps are sitting on acidic pages or in acidic binders.
Don