Has anyone ever heard of using a few different pieces of glass with sticky-back sandpaper on them to sharpen 3 blade heads?  The reason I say a few pieces is so you can have different grit paper and work your way to a higher number to get a sharper head.  If you have heard of it or done it, what grit papers are used?

That's usually called the "scary sharp" sharpening system.  Either thick float glass or flat granite for the base.

Here's a chart comparing the grip sizes of various stones to common paper

I have diamond plates in 120,220 and 325 grits.After the 325,I use wet or dry sandpaper laid on top of the plate.I go next use 400,then 600,1000,1500 and 2000,then strop on cardboard.You can take it as far as you like.Done properly,the 325 would do the job.

Some people use the wet or dry over glass,by wetting the paper.This helps it cling to the glass

What is the significance of glass?

flat working area

Glass can also tell how sharp it really is.. Takes time to get it down, but when You hear the right sound from sliding Your BH's across the glass You'll know it is way sharper then before...

Other then being flat it will sound if you have the very smallest wire burr edge left on the blades edges.

I still use glass when I get new BH's before sharpening them up for hunting.

cool thanks for the great info. That chart is awesome too.