Originally Posted by Dr. G
Agreed, newspaper works pretty damn good!
Some newspapers will cause glasses and mirrors to smear. There are several factors that play a role:
1. Newspaper (in the trade referred to as "newsprint") contains no solid components like calcium carbonate or silica, like higher quality paper. These minerals can scratch the glass, which can be confused with smearing.
2. Older newspapers were printed (and many still are) with oil based inks -- basically a cheap mineral oil. These too will smear or stain a window or mirror if a solvent or detergent is used to "clean" the surface.
3. Now the trend in printing inks for newspapers is to use water based inks. This allows newer and different types of pigments to be used too. These papers don't contain the oil of the older conventional inks and consequently are less likely to stain or smear a mirror or window.
There are two tests to tell which type of paper/ink combination is being used:
1. Hold the newspaper (or magazine for that matter) between your thumb and index finger for a minute or so. If your thumb/finger stains, you are using the old type of ink. The newer water based inks do not transfer on to your finger.
2. A related test is to gently rub the newspaper with a piece of typing paper. The friction will cause the older paper/ink combination to stain the typing paper. The newer water based systems are much more resistant to this type of test.
It does work, but it's not usually the best option, and there may be some serious drawbacks. Many people swear by this method, but honestly, I've never been a huge fan. It works in a pinch, but I much prefer other methods of cleaning glass and mirrors.
The truth is, that the newsprint can smear on the glass, and more especially on the frame of mirrors and windows. Newspaper doesn't hold together very well, when wet. And given the opportunities to recycle newspaper that we have, it seems to make more sense to repurpose the paper instead of tossing it into the trash after wiping down a mirror.
Bottom Line:If you love using old newspaper to clean your glass and mirrors, then have at it...but there's probably an easier way.