Darkslide material - again

I'm looking to make myself some 8x10 plate holders for the 2mm glass I use. My plan is to layer 3mm birch ply but I'm not sure of a material to use for the actual dark slide. I'd like to go for something about 1mm and plastic.

I've dug around on the forum but the discussions are quite old and not conclusive and mainly about replacing broken slides not new projects.

I've ordered a sample of 1mm HIPS black plastic sheet but really know nothing about different types of plastic available.

Any other suggestions of stuff that I can easily get in the UK? This is a kitchen table project so I can't do any machining.

(I appreciate that I will have to adapt the focus screen for the thickness of my handy crafted. The emulsion will be further back than film in a normal holder)

I've used black ABS for light tight constructions in the past. Don't depend on it to be IR opaque, however -- even at 700-710 nm it's almost as clear as glass.

For your focus adaptation, take a cue from LomoGraflok -- their product will ship with a "viewing frame" that both provides exact framing for the Instax Wide film, but also (relevant here) offsets the ground glass to match the setback in their film holder. Just slip an open frame under your ground glass for focusing, and Bob's your uncle.

The usual choice on this side of the great puddle is XX Garolite https://www.mcmaster.com/grade-xx-garolite/
I'm sure it, or something just like it, is available in the UK.
This advice hasn't changed in 100 years.
You should be able to score it with a utility knife and then snap it on the edge of the kitchen table. It is quite machinable with a hand drill and formable with a file and sandpaper.

Donald Qualls said:

I've used black ABS for light tight constructions in the past. Don't depend on it to be IR opaque, however -- even at 700-710 nm it's almost as clear as glass.

For your focus adaptation, take a cue from LomoGraflok -- their product will ship with a "viewing frame" that both provides exact framing for the Instax Wide film, but also (relevant here) offsets the ground glass to match the setback in their film holder. Just slip an open frame under your ground glass for focusing, and Bob's your uncle.

Click to expand...

Hi Donald. My plan is to make a ground glass holder from 3mm ply as well. I'll use it on my Intrepid so it is only two screws to switch it out for the original.

Nicholas Lindan said:

The usual choice on this side of the great puddle is XX Garolite https://www.mcmaster.com/grade-xx-garolite/
I'm sure it, or something just like it, is available in the UK.
This advice hasn't changed in 100 years.
You should be able to score it with a utility knife and then snap it on the edge of the kitchen table. It is quite machinable with a hand drill and formable with a file and sandpaper.

Click to expand...

Thanks Nicholas.
Searching around I think the equivalent over here is Tufnol and then people sell equivalents to that. They are forms of phenolic resin paper I believe. I may be wrong though!

Be sure to test the material for photographic activity before you get to committed to the material.
I suggest 2 types of tests:

1. Material contact
2. Fuming

Material contact consists of taking a piece of film that is when exposed at different levels (easily accomplished by exposing the film to a step tablet by contact or in a camera). Place the material in intimate contact with the film. Doing this by sandwiching under a piece of glass is an easy way to do this. Store the sandwich at elevated temperature less than 100° for 4 weeks. Process it and compare the results with a similarity expose piece of film that is been kept in a known safe condition.

Fuming is the same except rather than having the material in intimate contact with the film have them in a closed container separated by perhaps 1 inch.

Both tests are necessary. Some materials each type of test can give very different results.

If you pass both of these test can be confident that there will be very small chance of the material causing sensitometric problems.

www.makingKODAKfilm.com