Following some very helpful advice from Barry Say, I dressed a musette bag which I had made long ago from leather which was good but not as wonderfully airtight as the stuff that Jackie Boyce uses.
I have the impression that this has also improved the sound of the instrument, though this needs further scrutiny and the instrument is currently on loan. I’ve always preferred bags without dressing, out of distaste for their greasiness and the possibility of reed contamination which I do think is harmful. Perhaps I’ll have to re-think this.
It’s perfectly obvious that a bagpipe bag radiates sound and it’s a logical assertion that the state of the inner surface is significant.
What do others think?
Francis
P.S. Hotteterre recommends lard. Yuk!