I make a mask pattern for the printed board by the handwork. The mask pattern can be automatically created with the computer with CAD(Computer Aided Design). A mask pattern for the printed board which is manufactured at the factory is almost made using the CAD. In my case, a lot of same printed boards isn't necessary. Also, I like to make a pattern to solve a puzzle. So, I didn't use a CAD tool.
On this page, I will introduce CAD tool which is named "EAGLE". This tool is released by CadSoft Computer, Inc. in Germany. There are an English version and a German version. I am using the freeware tool of the English version. I am while studying this tool. So, there seems to be some mistakes in the description. Also, all feature can not be introduced. The description contents are only the feature which I use. For the details, please refer to the home page of CadSoft Computer, Inc..
Above-mentioned limitation is not the limitation which has hinderance for me to use.
My site is linked from CadSoft Computer, Inc. as "The Hobby Electronics from Japan".