A bunch of us, including astronomers from Kitt Peak, traveled to southern Baja for the July 11, 1991 total eclipse. The mexican government provided free mylar eclipse filters to the public. The mylar measured about 3" X 1/2" and were "framed" by a 1/2" of thin white cardboard. Mylar viewing strips can be dangerous because they puncture easily. Also, they are so small that there is too much bright sunlight hitting your face, making it difficult to view the eclipse.
A better filter is a piece of welder's glass, available at any hardware store. The glass measures about 3" x 1". We duct taped the glass to a hole cut into the center of a large, 12" X 8" piece of thick cardboard. This shades the whole face, and makes direct eclipse viewing safer, more comfortable, and easier to see. There are different grades of welder's glass. Get the darkest one. Don't forget that you can also use a pinhole shadow sharpener for indirect viewing. By the way, did you know that you can use a shadow sharpener to see sunspots on the sun? John Carmichael Tucson http://www.azstarnet.com/~pappas
