Re: [Cameramakers] bellows liner sheen

[Robert Mueller]

I am not sure this is possible but you can coat the stuff with thin layer of silicone of the sort used for sealing bathtubs, aquariums and.......  You can thin it with a considerable amount of mineral spirits (it takes a lot if you want to brush the result).  Add enough carbon black (I had success with about 10 % printers ink) to make thin layers quite dense.  This will fill the "pores" and also increase the resistance to some kinds of damage (and could be used to bond the fabric to the next layer).  If you now uniformly press this mess onto a suitable sheet of polyethylene or other non-stick material which has the surface appearance you desire, you will copy the surface in the silicone!  The real problem is finding a non-stick layer of something having the correct surface.  Much polyethylene is too shiny and the end result would be worse than you now have!  Still, if you can locate the correct stuff, I am quite sure the process will work.

There is a second point of view;  I cannot think of any reason to worry about the shiny appearance!  Yes, it reflects in a specular way, but if the source makes a broad beam, the specular reflection of that beam will be no less well spread out.  The main source of light is what bounces back from the film or film holder.  Certainly the film scatters light well and probably the black film holder is not too bad either.  It can easily be that a flat black surface reflects considerably more total light than your shiny one.
     It is hard to produce truly "dead" black.  Light traps offer the best hope and flocking is one way to reach this goal.  I have seen a bellows with partially flocked inner surface.  If you are good, maybe you can fl�ocking to adhere to the silicone (but hurry, before a skin develops!)

Bob



At 08:39 26.11.02 -0500, you wrote:

Hi,
         I am in the process of building a 24x24 camera bellows and I found this  wonderful material called "Emphatex." .   It  is a 2 ply coated breathable nylon material  used to make sports gear......It is extremely thin , light and subtle and is almost 100 percent light tight by itself, however  it does pass a very little light.. ... With two layers I am sure it will be completely opaque.. The question or concern  I have is that the material  has a slight  or dull sheen to it and I was wondering how critical do you think  it is to have a  liner in the bellows  that is dead flat black?
        If it is critical does anyone have any suggestions to dull the sheen..
        Also is there any recommendations for liners that are dead flat black..
Thanks,
 John Cremati