I got a nice email from Janet, who read my review of Studio by Sculpey's Super Slicer Blades and had a suggestion for my old dull blade:

"I read a tip once (from Lisa Pavelka I believe) that you can sharpen your blades by running them through a sheet of sandpaper. Maybe you can try that on your original blade."

Sure enough, a couple of Lisa Pavelka's books have blade-sharpening tips. And an online search found a few more. If you have a dull clay blade you need to sharpen, here are some resources:

• How to Sharpen a Knife With Sand Paper: While not specific to clay blades, this tutorial gives a nice overview of the process.
• Lisa Pavelka's Polymer Clay Extravaganza book has blade-sharpening instructions (she recommends 800-grit sandpaper).
• Glass Attic's Cutters & Blades page: Skip down to the section titled "SHARPNESS of blades" for some tips on keeping your blade at its sharpest.

I sharpened my old blade, and I have to say I'm happy with the results. I used a sanding block, starting with 400 grit sandpaper for my super-dull blade and progressing up to 1000 grit. It took all of about 10 minutes, and while I wouldn't say my blade's as good as new, it's definitely better than it's been in years!

Of course, you should be very careful sharpening these blades. And don't forget to handle your blade more carefully once it's sharp again. I don't wanna hear about any severed fingers!

Thanks to Janet for the tip. While it's sometimes tempting to just replace tools (especially the relatively-inexpensive ones), it's often better to buy better-quality tools to begin with and maintain or repair them whevever possible.