Map Definition

I was curious if anyone had a suggestion for the resolution necessary for an image to be used as a map without it becoming blurry when expanded to the size necessary for tokens to explore it.  I've not had good success with the images I've tried to use in the past.  When I get them to the point that they're appropriate for a token taking up a 5ftx5ft space, they're no longer sharp.

Aside from the best practices here's the basics: 1 square displays at 70 pixels resolution.  Roll20 allows for up to 200% zoom so if you want full detail at the highest zoom you'll need 140 pixels per square.  So for a 25x25 map you're looking for 3500x3500 pixels if you want full detail at full zoom.  This is probably more than is nesicary most of the time, but the maxium as far as what Roll20 can display.  That's my understanding of it at least.  Hope it helps and happy gaming!

If anyone is likely to know the answer to this it would be Gabriel whose maps are the primary source of my games! Since he has answered your question in detail I'll go ahead and close this thread :) Happy map making!