[Varangian (John)]

I did my 12" Dob with individual adhesive felt sheets from spotlight. The are very black and are A4 size so easy to install. You just peel the back off and stick them to the inside of your OTA. They are $2.50 a sheet and you can find them in the craft section. It cost me around $48 all up. If you don't want to do the entire OTA I'd suggest doing the small area behind your secondary (i.e. the section of the OTA you can see when you look through your focuser without an EP in. In terms of light bouncing around in there this is the critical area where you get light bounce back into the focuser. Cheers.