Music paper sizes

[Andrew Bernard]

Greetings List,

I measure my Henle Verlag books of Bach to be 235 x 309mm (+/- 1mm) 
[9.25 x 12.17 inches]. I rather like this size, but I cannot find it 
referred to as a standard paper size anywhere at all. Do my learned 
colleagues here know what size it is, or is it a trim down of a larger 
standard? Any help appreciated. It's almost 3:4 proportions but not 
quite, and the Henle books do appear to be exactly trimmed and all the 
same size.

I personally find this size to be the ideal for music, A4 too small for 
me, and A3 generally too big to sit nicely on the music desk.

Andrew