Just rerendered lowzoom tiles 6-11 for the northern part of Jylland, southern part of Norway, (33 19 6 12). This generated 1365 tiles with a total size of 6.6 Mb. Running those tiles manually through pngcrush reduced the size to 3.7 Mb. Worthwhile saving IMHO. Any objections to me adding pngcrushing to lowzoom.pl ? J.D. "Dutch" Schmidt