If your copy is to be photographed as you have typed it, it must be delivered to the printer in "camera ready" form. This form of "hard" copy "differs" from copy to be set in type in two ways. First, this copy is single spaced in order to offer the reader more information on any given page. Second, this copy must be both letter and punctuation perfect. If you plan to give your printer camera ready copy, you no longer have the luxury of making even one mistake corrected with a pencil mark.
Errors, of course, are bound to be made in your initial preparation. These can be minimized in the final published newsletter by having a second person look over your typed copy and by correcting all those you find. Some of these may be repaired using white-out. With more complicated errors, you may need to retype the entire line. Then, using a razor blade or similar edge, such as an X-acto knife, slice the incorrect line from your original copy and using a clean sheet of paper as backing, simply paste in the new line spacing it carefully between the lines above and below it. The finished newsletter will probably not show the line of cut. The best material for this pasting is rubber cement or glue-sticks not mucilage, as the latter tends to curl or wrinkle the paper.
In cases where you must deliver camera ready copy to a printer who, in photographing it will shrink the size of the overall block of type, don't assume or speculate as to what length of line and depth of column on your sheet of typing paper will finally result in the proper size block of copy in the finished newsletter. Consult with your printer. He will tell you exactly how many characters wide a line should be and exactly how many lines a column should have. This is simply another way of avoiding costly mistakes before they are made.