Restoration question: Original tape material used in plate holder light-trap shutter

[n4n0b1t3]

Hello all,
First of all, please feel free to correct my vocabulary — I'm not entirely sure about the proper terms for some of these parts.

I need to repair the internal light-trap shutter of my wooden 24×30 cm (roughly 9½×12 inch) double plate holder.
To do so, I had to unglue and disassemble the entire shutter mechanism — unfortunately including the original light-trap tape.

The plate holder came to me in quite a desolate state: many glued joints had come loose, and one of the shutter doors was cracked badly enough to let light through. I'm now in the process of bringing it back to a usable condition — with the goal of using it again for its original purpose: taking photographs.

I've attached a photo of the other (still intact) shutter. The original tape was remarkably well-preserved after more than 100 years and still fully flexible.

It was glued to the wooden parts using what seems to be a protein-based glue, most likely fish glue.
The tape itself appears to be a three-layer composite:

• the base layer is a sturdy white linen,
• on the wood-facing side, there's a black cloth (probably cotton or linen),
• and the outer surface is coated with a black, flexible, light-tight paint or rubber-like material that has aged extremely well.

I'm looking for a suitable replacement and would ideally prefer historically correct materials and a fully reversible process — especially since the original construction has clearly stood the test of time and served its purpose extremely well.

Any recommendations or experiences would be greatly appreciated!

[Jim C.]

It would seem to me that the dark slide ( shutter as you call it ) on your plate holder was cracked and repaired
at some recent time, that dark slide should look like a modern one, flat and smooth without a band across it.

If you want historically correct materials then your best bet is cannibalize another plate holder for the dark slides.
Otherwise Garolite sheets would the closest thing. The link below is just one source, Google for other sources
depending on where you are -
https://www.mcmaster.com/products/ga.../color~black-1

[n4n0b1t3]

Dear Jim,
thank you for taking the time to reply to my post.

First, I should explain that I’m working on a plate camera with a double-sided wooden plate holder. The darkslides on these are typically hinged, as shown in the image below. These cameras were generally used under a focusing cloth, and the hinge helped in two ways: it prevented the weight of the cloth from snapping the darkslide, and it made withdrawing the slide a bit easier.

The black cloth at the rear, as mentioned above, is an original part of the design and was not added later.


Best regards,
Peter

[Jim C.]

Hi Peter,

Now that you've posted a picture of the entire plate holder I'm not familiar with type of plate holder,
I have seen the one you have but I did not know that the dark slide was segmented since most of the pictures
show them closed. I have some single glass plate holders and they just have a single sheet dark slide.

Jim C.

[Vaughan]

I have several of these bookform plate holders. Bookbinder's tape might do the trick. Easy to find, relatively cheap.

Looking at the first image you posted, the holder seems to have been modified to have a rib on the top near the dark slide. That black part doesn't look original. It also looks like the sides have been planed down so it will fit into a more modern spring back. Not necessarily a bad thing, just be aware that it's not original.

[Steven Tribe]

I have lots and lots of these double plate holders (18x24 up to 30x40 cm’). Even though they are all well made with seasoned hard woods, they continue to dry out and crack. At least half of sets have dark slides with black paper strips covering the insides of the cracks done in the very early 1900’s! It is most practical to cover light entry with tape rather attempt to reglue the sections - you will change the dimensions of the dark slide and probably create new light entry edges and perhaps ill fitting slides.
Modified dark slides from this date are also common as there was no common standard size or camera fixing mechanism- and dark slides were often used on later camera purchase(s).
Hinges are often in quite good mechanical condition and sometimes have an overlap design when flat. Light passage through the hinge when it is “bent” is of no consequence in the cases.
Remember that we take only a small fraction of amount of exposures that the original camera/plate holders were subjected to! It is possible that careful use of dark cloths will protect against leaky plate holders and holes in the camera bellows.

[RJ-]

I'm looking for a suitable replacement and would ideally prefer historically correct materials and a fully reversible process — especially since the original construction has clearly stood the test of time and served its purpose extremely well.

Ross Burley of Burley Cameras in Sandgate is the only person I have seen using period correct techniques sourced in England. He has posted publically on his materials and techniques

Everything else I've tried: too thick; too thin; too bulky, too fragile. Consequently it's not unusual to have a high failure rate of these wooden bookform plate holders - par for the course with such 100year + old moving parts filming equipment.

[n4n0b1t3]

the holder seems to have been modified to have a rib on the top near the dark slide. That black part doesn't look original.

I should have mentioned, that the top part of the holder came loose and it was removed as I took the photo. I will need to repair the dark slide first before I start on the other issues. Fun fact, I am planning to build a spring back for my 18x24 camera.

[Vaughan]

I should have mentioned, that the top part of the holder came loose and it was removed as I took the photo. I will need to repair the dark slide first before I start on the other issues. Fun fact, I am planning to build a spring back for my 18x24 camera.

That black part isn't original to the holder. Bookform holders so not have locating ribs.