Thick and Thin Lines

Thick and Thin Line styles are sometimes used to enhance the visual impact of drawings. All adjacent edges should be Thin and all outside lines Thick. An easy way to work out which line to use is to imagine a Spider crawling over them.

If the Spider crawls over an edge and you can still see it then it should be a Thin line. If the Spider crawls over a line and then you can't see it any more then it should be a Thick line.

The same rule applies to both rectangular and rounded shapes

Line Styles 218