: I tried using one of those laser line gadgets instead of the string
: trick, but I found the type with a lens over the lazer doesn't
: deliver a perfectly straight line, so back to the string . . .
: there are better types that spin the laser on a motor to deliver
: a truly straight line but they are too clumsy and quite a bit
: more expensive. Also, if the surface they are projected on is
: not perfectly flat the line will not be straight anyway.

String's simple.I forget anything that's not simple [Red Herring]...Also,string shows you just what you want to know,nothing more or less.