Now, finding acid in any uncoated paper is as easy to do as a swipe of this pen. Yes, it's easy, but it's also effective. It works.
Use this pen to test bond paper and others you might use for writing, printing, copying, or use it to test enclosures for your important papers inside. Instructions included are easy to follow, and you can tell the amount of acidity by the color of stroke made.
This easy, convenient method allows you to tell the difference between what is safe (i.e., 'neutral' or 'alkaline' or 'permanent') paper & board and what is acidic. Simply draw a small line on the material you wish to test. The┬áindicator solution in the pen will turn a specific color 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 (or long term safe storage).
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. However, in order to last for centuries in today's polluted air, it must have an 'alkaline reserve.' Usually, this means the paper must have a pH of 7.0 or greater.
Please note: unreliable results may occur on colored or coated papers.