Photo / painting on curved glass

Conservation Issues
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Not your average framer
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Photo / painting on curved glass

Post by Not your average framer »

A regular customer has brought in a unusual item where the image is on the reverse off a piece of curved glass. I have never seen one of these before, but I believe I have pretty good instincts when figuring out what most things are. In this case, I believe this to be an early type of sepia photographic print, (possibily later Victorian era), which has been painted from behind so that the painted on colours show through the non-opaque areas in the image. I have no concerns about the condition of this item and consider it safe for re-framing in it's repaired, original frame.

When it arrived, there was a piece of old and well browned (no doubt acidic) pulpboard on the back which had been taped in place using an early type of black tape, (Victorian photo album tape?), taped around the front of the glass and onto the rear of the pulpboard.

I have already removed and discarded both the pulpboard and the tape, which I must now replace. My assumption is that there may or will be photo-chemical activity / compatiblity issues concerning what I use to replace the afore mention discarded materials.

My best guess is that the rear of the photo is painted with an egg albumin based paint and perhaps the photographic medium would also be egg albumin based. For this reason, I am not entirely happy about using an archivally safe tape with a water based adhesive, in case any moisture may be transfered to the suspected egg albumin based materials. However I am even more concerned about using anything which includes any self adhesive materials, due to chemical compatiblity or out gassing contamination issues.

I am current thinking that I will use the archival tape whic includes a water activated starch based adhesive and will check that all the water has been fully absorbed into the paste, before taking care to ensure that the tape cannot come into contact with the any materials on the rear of the glass. I am also thinking that I will replace the discarded pulpboard with a cottom rag museum mountboard.

I have found it very hard to find any specific guidance in any of my reference books or elsewhere. An experienced conservator I know also agrees with my thinking and believes that I am intending to do all the right things, but she has never encountered anything like this either.

Beside welcoming any additional advice, I thought this would be a potentially informative subject for discussion and exploring relevent issues.
Mark Lacey

“Life is short. Art long. Opportunity is fleeting. Experience treacherous. Judgement difficult.”
― Geoffrey Chaucer
Nigel Nobody

Re: Photo / painting on curved glass

Post by Nigel Nobody »

I'm not sure I understand exactly what this looks like, but I wonder if it is absolutely necessary to tape anything back in place at all, if it's going back into a frame?

Is it not possible to place the backing over the back of the glass (without tape) and use tabs to hold everything in the frame?
Not your average framer
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Re: Photo / painting on curved glass

Post by Not your average framer »

Hi Ormond,

Well, that's how it was originally framed and I feel inclined to do likewise in case there was a good reason for doing so, which I don't know. Also the frame is not curved to match the glass, so sealing the glass to the mountboard would prevent entry for dust and insects, etc.
Mark Lacey

“Life is short. Art long. Opportunity is fleeting. Experience treacherous. Judgement difficult.”
― Geoffrey Chaucer
Roboframer

Re: Photo / painting on curved glass

Post by Roboframer »

Get some photos up :roll:
WelshFramer
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Re: Photo / painting on curved glass

Post by WelshFramer »

NYAF. Not quite the same thing but this article:

http://www.pictureframingmagazine.com/p ... toPres.pdf

in this month's PFM might give you some ideas.
Mike Cotterell
Neuadd Bwll Framing

http://www.welshframing.com
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Not your average framer
Posts: 11013
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Re: Photo / painting on curved glass

Post by Not your average framer »

I'll take some photos tomorrow!
Mark Lacey

“Life is short. Art long. Opportunity is fleeting. Experience treacherous. Judgement difficult.”
― Geoffrey Chaucer
framemaker

Re: Photo / painting on curved glass

Post by framemaker »

I think these are called crystoliums (probably spelt that wrong).
I have a family friend who collects them, so I have seen a good dozen of these, usually for repairs to the frames. Generally the ones I have seen have been mounted in wide gilt slips. I have one at the workshop at the moment, which is just fitted in an ornate gilt frame which has an integral bevel slip.

I have seen a couple with those gilded heavy card mounts, so with no rebate these were secured to a pulp board undermount with gummed tape across the front of the glass on all four sides, with some strips of filler board to support the glass and then the gilded mount on top.

I will take a photo of the one I have here, when I get a minute...
Not your average framer
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Re: Photo / painting on curved glass

Post by Not your average framer »

Here are the photos:

The first photo shows the item and frame. The frame was falling apart at all four corner mitres and I have already corrected this, but there is still some damage to fill and the frame will be completely re-finished to exactly match the original finish.
Curved glass 1.JPG
Curved glass 1.JPG (28.65 KiB) Viewed 15120 times
The second photo shows the glass removed from the frame. The glass is covex in both planes and has the greatest degree of curve showing at it's centre where the deviation from flatness is perhaps as much as 10mm. Sorry it's not such a clear photo, due to reflections of the back of our sofa.
Curved glass 2.JPG
Curved glass 2.JPG (37.21 KiB) Viewed 15120 times
The third and final photo shows the reverse face of the item. The media used to pigment to back is very highly matt all over and show no signs of any loss of pigment or damage. I have never seen one of these before and know very little about it at all.

My customer bought it at auction after outbiding others who wanted it too! I am led to understand that these sort of items are quite rare and sought after.
Curved glass 3.JPG
Curved glass 3.JPG (51.45 KiB) Viewed 15120 times
Mark Lacey

“Life is short. Art long. Opportunity is fleeting. Experience treacherous. Judgement difficult.”
― Geoffrey Chaucer
framemaker

Re: Photo / painting on curved glass

Post by framemaker »

Been in touch with my friend who collects these, and its called a crystoleum

Google it, there are a number of good bits of info

this link will be of interest regarding conservation and reference to the only known copyrighted recipe, although it does not go into detail:

Conservation of a crystoleum (Word document)
framemaker

Re: Photo / painting on curved glass

Post by framemaker »

Looking into this a bit more it seems there are two publications on the process, materials and how to:

Crystoleum by Alberta Caspar
including all the improvements and practical instructions for acquiring this popular art perfectly, withfull information on the method of mixing and applying the colors

and a later work, which according to NPG was probably based on the above book:

Crystoleum painting by Alston's new process by Albert Alston
the most improved method of transparent photo colouring on convex glasses to imitate miniatures on ivory.

Both published a hundred years ago or so, but maybe there are some copies out there somewhere?
Not your average framer
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Re: Photo / painting on curved glass

Post by Not your average framer »

There are some relevent downloadable transcripts available for those who are interested:

http://chestofbooks.com/crafts/mechanic ... nting.html

http://pinnacletimes.wordpress.com/2006 ... -painting/

http://chestofbooks.com/crafts/mechanic ... nting.html

As I suspected, it appears that the basis of the technique is an albumen type photo graphic print, (a lucky guess on my part).

However, the paint used for the colouring is an oil paint, not albumen based paint as I suspected, (a wrong guess on my part).

This now gives me confidence to replace the thin card on the back of this painting, as any photo activity concerns will be of less significance than I first speculated. I will therefore use cotton rag 1 ply museum mount board and feel safe to do so.

Those who are interested, may notice that the paper backing to these albumen prints were removed by sandpapering. In another internet article an antiques website claims that at one time there were thousand of these made, implying that these things were almost mass produced.

The mind boggles! I would not like to try and sandpaper the backing paper off of even one of these, let alone in volume. I guess people were more patient in those days.
Mark Lacey

“Life is short. Art long. Opportunity is fleeting. Experience treacherous. Judgement difficult.”
― Geoffrey Chaucer
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