I have been touting this pen for years in this community so kudos to him for at least promoting the pH testing.
But he completely misses the boat on acid paper and the video, other than encouraging folks to test their materials, is probably doing more harm than good. In my opinion the video is terrible. Is bad information better than no information?
First, you have to understand what causes acid in paper. It comes from lignin, the cellular component in plant walls which make the cells strong (and allows plants and trees to stand vertically). As lignin breaks down OVER TIME, it creates acids. So paper manufacturers throw in some buffer, typical bicarbonates, into the paper slurry to neutralize the pulp. This is great, it adjusts the pH higher and brings it into the base (or alkaline) side of the scale at the time of manufacture.
But the buffer that has been added at time of manufacturing does not last forever. The lignin in the paper continues to breakdown over time and once the buffer has been used up a tipping point is reached and the acidification process pushes the pH back into the acidic side of the scale. This is a big reason that 'acid-free' paper marketing is meaningless. Who cares if the paper is 'acid free' when you buy it? You want to know that the paper will STAY acid free over time. Doh. I guess it is fine for anyone who is clueless and/or wants to pretend they are making a good decision when buying cheap crap paper.
So you do not simply test your paper once, call it good, and then walk away. You test and continue to test. The video misses the most critical thing about paper and acidification, that it changes over time.
Archival paper has no lignin, they do not use wood pulp, recycled paper, or other sources which contain lignin. This is what makes true archival paper costly. Buying 'acid free' paper at Staples, testing it once as shown in the video, and then thinking that your stamps are fine for the rest of your life is wrong and having a video which implies this is doing more harm than good. If you are going to publish information you ought to at least do simple and preliminary research on the topic you are covering. Don
It is a cheap pen, I consider it a 'consumable'. Plese note that it also has an issue with picking up paper fibers on the tip over time (the tip will actually change color); I assume that this kind of contamination can result in inaccurate markings. So I just frequently replace them. (If anyone has every kept a fish tank, swimming pool, or hot tub they know that you have to constantly check pH over time and that replacing your test kit each year is good practice for accurate reading. How this fellow missed mentioning of any of this critical info in his video is beyond me.)
I test everything including binders and slipcases. Stamps and cover can tone without direct contact, sitting in a cardboard box or a cigar box can great damage stamps with them never touching theses surfaces. Paper breathes, it is constantly trying to normalize with atmospheric conditions it is sitting in. If the surrounding atmosphere has a high RH and the paper moisture content is low, the paper acts like a sponge. Coatings on things can give false readings (in either direction), be sure to test areas like the edges of cardboard if it is coated. Do not be surprised to find that many album slipcases are made of cheap acidic cardboard. Why spend money on costly archival paper and then throw the entire album into an acidic cardboard box? Don
Edit; Keeping a great, STABLE environment goes a long way to forgiving those who cheap out on buying quality paper. Stability in temperature and RH is the key factor, it stops the paper from constantly trying to normalize with atmospheric conditions that are surrounding it. I think that in many situation collectors are aware of environment conditions and this covers up many 'sins'. But the trouble can become acute when the collections move into the hands of family members and materials end up in 'less than ideal' environment (basements, attics, cold back rooms, etc.)
I found what tested positive as more interesting than what did not. He found some sales cards. manila stock pages, glassines, and the "Supersafe" hinges tested as acidic. He did not test Dennison hinges.
Glassines, manila pages, and hinges are staples for many collectors yet most discussion I see is on album paper.
Scott Pages? Minkus Pages? Mystic Heirloom Pages? Palo pages? Lighthouse Stockbooks? Lighthouse Vario-F and G Binders/Slipcases? Vario Pages? For self-produced albums (Steiner), what is the "best" option?
Have the above items been tested?
From the conservation standpoint, what is best practice, for pages and albums? Those are the questions I have, anyway...