Philip writes –
Actual-size Electronic Breadboard templates in SVG and other formats. A while ago I was wanting to document some breadboard circuits I was working on and went looking for an SVG-format electronic breadboard template I could use with Inkscape. The only file I found didn’t seem to be actual size so I created my own. I’ve just uploaded a variation of my original design that also includes connectors from the Arduino Diecimila alongside the breadboard. When printed at actual size the dimensions and layout of the holes on this template should be able to accept actual component leads. The template files are in the Public Domain. The files are available in SVG, PDF and PNG format and you can either use an editor like Inkscape to layout your designs or print them out and draw on top. (Because they’re actual size you could lay out the actual components on them too.)
Electronic breadboard templates – Link.