<r>I had the same question / problem today and I solved it by <B><s>[b]</s>creating a grid in a vector drawing program<e>[/b]</e></B> (I used the free software <B><s>[b]</s><I><s>[i]</s>Inkscape<e>[/i]</e></I><e>[/b]</e></B>) and exporting that grid as a <B><s>[b]</s>bitmap<e>[/b]</e></B>. Then I ...