Wall Thickness Test - range 0.5mm to 5mm steps 0.5mm

Results on Reprap Mendel / Pronterface
0.5 - didnt appear :-/
1.0 - tidy and accurate - good for thin walls
1.5 - tidy but undersize
2.0 - leaves gap along middle
2.5 - tidy and filled - good for higher walls
3.0 - leaves gap up middle
3.5, 4.0, 4.5, 5.0 - all tidy

...and had real trouble with 5mm font :-\

I'm now using Slic3r so will try this again and see how it looks