I am Zach Johnson, a designer for Schadenfreude Games. We are currently working on a large strategic board game that consists of a map approximately 3 ft. wide by 2 ft. tall. We have made a hand drawn map, but want to move it into the digital realm for a possible print and play for playtesters, I imagine sending interested persons a pdf with the map spread out on several 8.5x11 pieces of paper which they can simply print out and connect together. I dug into the tutorials hard, and have produced an amateur looking map using GIMP, but very small. In one such tutorial I read that to have print quality for a map you should set the resolution to 300 pixels per inch. I did this for a full sized map and the file size for the blank slate was 1.3 GB! Needless to say it froze my computer for several minutes, after regaining control I closed the program and resumed playing around with a smaller image.

Question:
If I am to print out an image (I don't need publisher quality, just playtest quality) how many ppi should I have so it doesn't look terribly pixelated? Or is there some trick to make it in parts? although I'm not sure how to line them all up then.

Thanks in advance!
Zach