Paul, I understand it to be covering surfaces (usually the inside of tube assemblies) to reduce light reflections and scatter. Usually with a rough material. There are some specialist materials, it seems. I've seen some use a textured paint or finish. Paul Haese explains that he used a black adhesive felt. Look at reply # 20 in this thread on this other forum:-
http://southcelestialpole.org.au/for...?topic=4644.75
for photographs through his tube before and after the addition of flocking. Pretty amazing difference, hey?
Eric
