I'll start out by saying when it comes to choosing, making and addressing knobs for lids, I am not batting 100%, that being said, I have become aware that fewer get it right than those who get it wrong. With knobs as well as other pots, addressing knobs can seem a bit like; the good, the bad and the ugly; there is no hard and fast rules or science to getting varying pieces parts to work together and lidded pots, like teapots are a good example of that. A good knob should be an extension of the lid and of the pot, it should compliment the overall form as well as preforming a function. Some knobs are organic and seem to just "sprout" from the lid and form and others are intentionally made to look added to the form, yet still are tied in to the pot to create a cohesive presentation.
I began thinking about this the other day after a fellow collector asked me my opinion regarding a Shigaraki mizusashi. The pot was very nice and was exceptionally well fired and by a big name potter but the knob seemed like an after thought and seriously detracted from the overall presentation. If you imagine a somewhat irregularly and organic pot with a small section of pipe like knob sticking out of the lid you can get the picture. It seriously looked out of place on the pot and I wonder what the potter was thinking when he made the lid and knob? I know it is easy to play arm-chair quarterback after a pot is made and recognize my own short comings but the only way to get these details right is to study, look at lots of pots and make even more and always remember the devil is in the details and everything a potter does is the details.
Illustrated is a picture a friend sent me of a very fine Iga mizusashi with the potter who made it; Kojima Kenji. This pot is from a December 2014 exhibition of Kojima-san's pots and it is obvious that the knob is an organic extension of both lid and pot. The knob appears to fulfill its functional requirements while making a visual statement as well, all in all a well conceived and executed mizusashi with a great keshiki and color.