My soap collection has been slowly building. One thing I’ve noticed is that the bars are rarely uniformly cut. No matter how hard I try that cheap little soap cutter is just doing a poor job.
I’m talking about one of these bamboo box jobbers with a planer:
It seems like it would work well, but there’s too much play in the gap where the knife goes. And these boxes are never tall enough for your soap, so the first inch or so of soap cutting you’re pretty much guessing where you should cut until you hit the slot for the knife.