It may look better to have twill covered hose, but the main reason for
the twill is to keep the hose from collapsing. I tried that gray crap
Durrell [PPCo] sold and found that if used over a certain pressure, as
in Duo-Art pianos, it would suck shut. I found I could only use about
3 inches of it and then had to put in PVC or other solid tubing with
gray hose on the ends for connection only.
Durrell said at the time he could no longer get twill hose because it
was not being made after his supplier went out of business. I am not
sure I believed that, especially when he would make one order of
hundreds of thousands of dollars at a time (a fact). I am glad he has
it once again. Schaff/Apsco and Organ Supply Industries are the only
sources I have used for it. One thing I despised was the 16 shades of
purple that PPCo uses. I usually just spray paint it black so it all
matches, or dye it with India ink or NGR stain.
I find that I too use the Reproducer size most. That is usually
1-1/16" ideally. For some reason you could only get 1" or 1-1/8".
One is too tight and the other is looser than I prefer. I would also
like to know if someone stocks that size. I am not going to quibble
about the cost of it. I usually have to pay more for higher quality
supplies. However, I will look for similar quality for less money
whenever I can. If you have had any items made specially for one
brand of piano you understand how items will cost way more than you
would expect to pay sometimes. I do not think that the Durrell motto
of charging 600% or more markup is good either.