After a few year's use of the Shapton 30K Pro hone, it lost it's "mirror" gloss on the used (non-logo) side. This definitely impacted the sharpness of my straight razors...the magic was gone and it felt like I was shaving with a razor honed on an 8 or 10k hone. How to polish the hone back to a 30k surface? Use a diamond hone like the one Shapton provides for the "new" ceramic glass 30K hones. Avoiding this nearly $300 expense, I found a cheaper way to recondition my 30k purple(and 16K cream) hones. For $8.00, I bought some Cerium oxide from a lapidary supply store, a tough powdered orange substance (like a rouge) which when placed on the lap, will do a great job on these hones. It appears to come in one grit....ultrafine...and is used to polish stones in lapidaries. Watch the adhesive nature of wet Cerium oxide slurry. The hones must be moved in figure-of-eight motions without pressing down, else they will adhere to the wet lap as if they are super-glued to it. A little patience will result in a nice polish and excellent re-truing of the hone's surface.