I have Garmin Topo Australia on my Etrex but for whatever reason dont have printing permission for the maps from within Basecamp. Now you can take a screen shot but the image size is pretty small and I found you needed to zoom way in to get any detail which reduced the coverage.
My solution was to take several screenshots and join them together, highlite the contours/water, draw a grid and this way produce images 5000+ pixels wide/high for printing.
I have some programming skills so the process is mostly automated from within a small app I wrote for Windows which takes the screen shot, moves the map and stitches them all together. then by using two waypoints in the top left and bottom right corners calculate and draw the grid.
Needs some minor tweaking but so far I'm pretty pleased with the results. Any feedback welcome.
Heres a sample image which is greatly reduced in size from the original so it could fit on this forum: