Parallels - what are the differences?

[eightball]

I usally use 1/8 parallels. ive used strapping, foam, grease, etc to hold them in position. I have a spring set that i use more than anything to support the parallels. My favorite parallels are a 1/16 thick power hacksaw blabe that i ground in the surface grinder. Took all the teeth off, flipped em over and lightly ground the other side. I have used them for 28 years. I actually ground two sets at once so all four are the same height.