The crinkle paint hides fingerprint marks, I think. And maybe there's the fact it doesn't produce reflections -- easier on the eyes of the typist.

Yes, a good example of this is the Imperial Typewriter Company who were one of the few typewriter manufacturers to continue throughout the war.  They switched from the glossy black enamel finish to crackle finish black on all their models in 1940 and never went back.  I'm pretty sure that it was because the castings did not have to be linished and polished to a super-high standard (as when using gloss black enamel) because crackle finish will hide a multitude of small imperfections.  For the same reason, rebuilt secondhand typewriters of all makes were 'modernised' with this finish in the late 1940's.

Greetings All The thing I’ve found and like about Scrubbing Bubbles is the almost instant indication of how dirty the finish is. When first sprayed on, the foam is white but will turn varying shades of yellow through brown depending on how much dirt and or nicotine has accumulated on the finish. A quick scrub with a reasonably soft bristled brush followed by a rinse off with a spray of hot water and the finish is pretty well clean. Just dry it thoroughly and you’re ready to reassemble. All the best, Sky

I read somewhere in the typosphere about using toothpaste and a toothbrush, so I gave it a go. It does take patience, but at least you know nothing horrible will come of it. Plus you get the minty aroma!

Uwe wrote:

Isn't toothpaste a mild abrasive? I like the idea of a soft bristle toothbrush - I always have a couple in the toolbox - but not sure about the toothpaste.

Toothpaste is slightly abrasive, I used to use it to clean the chrome on my motorcycle and cars. It was a lot cheaper than using chrome polish and worked just as well. I have always cleaned the letter slugs with methylated spirits and a toothbrush. I have no idea what it might do to the paint finish on a 1930's typewriter but I always used to put a drop of meths in a bucket of water when leathering off the cars after the weekly wash to prevent any water marks. It certainly didn't seem to do any harm to the Rolls Royce or the Bentley I had to clean every Sunday morning in my youth. I always use a non abrasive polish, Simoniz Original, probably the hardest car polish to use though but my typewriters are gleaming bright if nothing else.