Will my knives need additional polishing after polishing on a 5K or 6K whetstone?
For kitchen knives, I have found that going beyond 12K grit yields no perceivable performance upgrade over 6K grit. The higher the finishing grit you go, the mirror-like the knife’s edge becomes. This will not translate to cutting performance if the knife was poorly sharpened at the 1K grit level. So, before investing in very expensive polishing whetstones, make sure you are happy with how sharp your knives are with just a 1K grit whetstone. If you already have a 5K-6K polishing whetstone, and considering an 8K polishing stone, understand that you are making a visual upgrade, more than a performance upgrade for your knives.