I have used these templates for ball ornaments and also for some three sided ornaments.
On my blog pages I refer to these shapes as leaf shapes or petal shapes or even sections. However, the proper name for these shapes, which is the area between two overlapping same sized circles, is a lens. The following links are for templates that one can shrink or enlarge using common word processing program.
The first download has instructions that should allow you to adjust the size of the template using MSWord. You should be able to make a template for any lens shape, as long as it fits on the paper. (Note. Although this document appears as two pages on the preview screen it should download as one.)
Adjustable Lens Template using MS Word
The second download has instructions that should allow you to adjust the size of the template using Open Office. (Sorry. There's no preview available for this download.)
Adjustable Lens Template for Open Office
If you find that you can not adjust the template on any of these documents you can download these templates for four, six and eight piece ball ornaments. You will not be able to adjust the size of the lens before you print but hopefully you can use a photocopier to reduce or enlarge the template.
Four piece ball
Six piece ball
Eight piece ball
November 2012 P.S.
I found a blog that includes an online lens shape generator. If you enter the diameter and the number of segments into the boxes it will generate the patterns for you. You can find it at,
http://helimadoe.com/2010/12/christmas-is-coming/#ChristmasBallPatternGenerator