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oskar recommends filling the whole thing (including lather bowl) with warm/hot tap water to preheat it and then empty and fill the cavity with hotter water
That way you avoid thermal shock, but...

they are much better pics on his website...
Schwarzweisskeramik

It must have been 30 minutes, the brush started to cool but if i quickly re-whipped, it rewarmed the lather on it.
It was my first...

Well this turned up this week...

Black doesn't photograph so well, well not with my crappy camera in the bathroom just before/during a shave. But let me assure you the finish is spot on!
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