I've visited various websites about the 3-site skinfold test, but none seem to deal with my issue. I'm not exactly light (non-athletic 220 lb at 6'), and I'm trying to use fat percentage for my progress. However The sites I've read don't seem to clarify how much one's supposed to pinch. By starting my pinch an inch wider or narrower I can drastically alter the mm measurement the caliper records (+/-25% on the mm measurement), and I can't find any clear instructions as to how wide the pinch should be, leaving my numbers inaccurate.
I very well might be doing something entirely wrong, which I'm willing to correct, but I don't know what that is to fix it. I'm more than willing to give more detail if I can be directed towards what to provide.
The site that I found the most helpful (if a tad... goofy) is the following: http://www.free-online-calculator-use.com/body-composition-calculator.html