On Fri, Feb 24, 2012 at 11:54 AM, Glynn Clements <glynn at gclements.plus.com> wrote: ... Thanks for the suggestions, will study them. > So e.g. 10,000 maps with 1000 columns would require an extra 200MB; > 10,000 maps with 10,000 columns would require an extra 2GB. We have 19,000 x 22,000 pixels here... 13,000 maps. Markus