[sdiy] Addition: surface of keyboards

[jhaible at debitel.net]

Just to be more precise, it's the *tips* of my finger which ache, so
I don't think it's a problem with force, weight etc. I think during fast
playing the fingertips slip on the surface and either there is an
unpleasant effect on the skin from the slipping itself, or
force is applied to parts of the fingertip where it normally wouldn't
(closer to the nail ??) because it slips from its normal position ...

JH.