Filters, Resin vs. Ployester, and Portra Films, for Copying Slides

I plan on buying a 3x3" 85B filter for my Illumitran copier, and wonder
whether there's any reason for choosing a polyester vs. a resin filter
for same. Prices are close, neither will be used in front of a lens.

For the copier, I've made numerous copies of a calibration slide at
various F stops, trying for a constant F:11, using various neutral
density filters. Other, personal slides were also used. I'm close enough
now to start using Kodak Professional Portra 160NC lower contrast film
(I hope) to make prints from both 2D and 3D slides. I also will compare
the results I get from that film with Kodak's Professional Portra 110T
tungsten film with the 85B filter.

Any comments on the choice of F stop and type of film would be
appreciated. Other 35 mm film companies films would be of interest based
on comments from you folks.

I know there are "better", professional, copying films (35 mm) out
there, but I'm not sure I want to fool with them based on the data
sheets I've looked at.

Dan Wenz wrote:

I plan on buying a 3x3" 85B filter for my Illumitran copier, and wonder
whether there's any reason for choosing a polyester vs. a resin filter
for same. Prices are close, neither will be used in front of a lens.

For the copier, I've made numerous copies of a calibration slide at
various F stops, trying for a constant F:11, using various neutral
density filters. Other, personal slides were also used. I'm close enough
now to start using Kodak Professional Portra 160NC lower contrast film
(I hope) to make prints from both 2D and 3D slides. I also will compare
the results I get from that film with Kodak's Professional Portra 110T
tungsten film with the 85B filter.

etc.

That's "Polyester", folks, and Portra 100T, not 110T :-(