Using triumph paper cutter

When I sharpen a conventional knife blade, I test it to see if I can shave the hair on my arm. Much as one would shave with a straight razor. The test is in the cutting. Not a recommended method for testing a paper cutter blade. Still, the test is in the cutting. Does the blade cut the paper easily and cleanly? Most people fail to remove and sharpen their cutter blade often enough. Just as with a kitchen knife, they get by with a duller and duller knife. Not good practice.
A well sharpened cutter knife will cut through a ream of copy paper with a nice even cut. About 200 sheets may be a better number to work with.
Place two or three sheets of chipboard or other scrap stock on the top of your stock to be cut. Do not use corrugated cardboard. Bring the clamp down tight and make the cut.
A dull blade will pull the top of the stack away from the back gauge and the cut pieces will not be a uniform size. If that happens, you know your blade is past due to go to the grinding shop.

I do find that if I cut more than 20 sheets of 100# lettra it will pull off of the back gauge.
Anybody know a shop capable of sharpening my blades in San Diego?

Here’s an illustration to go with Inky’s good advice. However, I avoid using chipboard as I believe it speeds dulling of the knife.

cuttingPaper.png

With Lettra and other soft papers, 100 or fewer sheets is better. Make a few more cuts, take a bit more time and get better results.
Look in the Yellow Pages under Grinding or Knife Grinding. Ask the local print shops who does their work. Or, ask the cabinet maker who grinds his planer and joiner knifes.