Wetplate darkbox shroud/camera bellows liner replacement fabric found

[smieglitz]

I've found a replacement for the shroud/bellows material Freestyle and Porter's used to sell. It is called BK5 fabric and is available from Thor Labs. It comes 60" wide x 3 yds long for $44.20 USD. Other continuous lengths can be specified. The material is 0.005" thick making it lightweight and flexible. I tried to stretch and scratch it, but it resisted that minor abuse and seemed pretty sturdy.

I requested a sample last week and they sent one to me very quickly. It is very similar in weight and flexibility to the old stuff sold by Freestyle and Porter's. The rubberized side is a bit shinier than the old fabric, but it should work well.

I tested it by exposing a piece in contact with some photo paper in a contact printing frame. For the first test, I stuck the frame about 2" from a set of UV BLB lamps in my handmade exposure unit for about 5 minutes. After developing the print, the weave pattern of the fabric was discernible but the fabric only let through enough light/UV for it to be a very light gray while the unprotected area went black immediately.

I ran a second test exposed in the contact frame under normal fluorescent room lights for about 20 minutes. I saw no evidence of exposure on the side covered by the fabric (either in a single or double layers).

I'll probably order about 12 yds of the stuff immediately to have on hand.

Edit: I just read about some other tests done with this fabric on other forums. As a result, I have to correct the information.

After reading about a flashlight test, I retested with a laser pointer. It went through the new BK-5 stuff but not a piece of the old stuff I had from Porters. I thought the paper test would be sufficient. Sorry to disappoint. I hope no one ordered this stuff because of my post.


Joe

[billschwab]

Cool Joe... I'm finally planning to build a box and this will help. Appreciated.

[smieglitz]

I just read about some other tests done with this fabric on other forums. As a result, I have to correct the information.

After reading about a flashlight test, I retested with a laser pointer. It went through the new BK-5 stuff but not a piece of the old stuff I had from Porters. I thought the paper test would be sufficient. Sorry to disappoint. I hope no one ordered this stuff because of my post.