52 Weeks of Historical How-To’s, Week 50: How to Varnish a Collodion Plate

Back in Week 15 of our Historical How-To’s, we created some collodion wet plate negatives. It is here that I must confess we did not actually finish the job. Any collodion photographer of the Victorian or modern age would tell you that if you want to keep your image you must varnish it. This is where we possibly failed our readers (or left ourselves open for a follow up blog perhaps?). Collodion images are notoriously fragile, prone to scratches and tarnishing.

Pair of portraits, mother with small child [PHtempSB1-1]. Unvarnished half of image shows extensive tarnishing.

Pair of portraits, mother with small child [PHtempSB1-1]. Unvarnished half of image shows extensive tarnishing.

Unvarnished portion of image shows curling and flaking of image layer resulting in the eventual loss of the image.

Unvarnished portion of image shows curling and flaking of image layer resulting in the eventual loss of the image.

Special Collections has recently acquired about 250 early collodion negatives, dating to about the mid 1850’s, taken at the home of Lord and Lady Kinnaird at Rossie Priory in Perthshire. The Kinnairds were early champions of photography and, besides practising photography themselves, they encouraged the development of the early processes here in St Andrews with the help of Sir David Brewster, Dr John Adamson, Hill and Adamson and Thomas Rodger.

Stereoview of Lord Kinnaird (holding lens cap), likely with Lady Kinnaird (behind camera) and other photographers and darkroom technicians posing with an 1853 Ottewill folding camera in front of their dark room at Rossie Priory.

Stereoview of Lord Kinnaird (holding lens cap), likely with Lady Kinnaird (behind camera) and other photographers and darkroom technicians posing with an 1853 Ottewill folding camera in front of their dark room at Rossie Priory.

Some of these images came to us unvarnished or partially varnished. As the process of varnishing a plate takes almost as much time as making the image itself, plates were probably not varnished unless they were likely to be used for printing. At first glance, many of the Rossie Priory images appear to be stereoviews, however upon closer examination about a third of them are actually pairs of images, most likely taken with a stereo camera but making two separate exposures of slightly different poses. In most of these cases only the better pose was varnished and the less-flattering pose left to the elements.

Pair of portraits, an elderly woman [PHtempSB1-5]. Unvarnished half of plate shows tarnishing, and extensive, intentional scratching.

Pair of portraits, an elderly woman [PHtempSB1-5]. Unvarnished half of plate shows tarnishing, and extensive, intentional scratching.

Stereoview of two women, one holding a baby [PHtempCB-A-16]. Unvarnished image shows extensive scratches. As the two women here are both slightly out of focus the photographer likely was not planning on using the image. Happily, the plate was not destroyed as the Rossie Priory darkroom and skylight studio can be seen clearly behind them.

Stereoview of two women, one holding a baby [PHtempCB-A-16]. Unvarnished image shows extensive scratches. As the two women here are both slightly out of focus the photographer likely was not planning on using the image. Happily, the plate was not destroyed as the Rossie Priory darkroom and skylight studio can be seen clearly behind them.

So promptly we decided to varnish our plates to ensure their long-term survival.

The varnish is a mixture of crushed up gum sandarac mixed with alcohol, and some lavender oil added to ensure it doesn’t dry too brittle or hard.

To make sure the varnish will spread evenly across the plate both the varnish and plate have to be warmed to similar temperatures. The vial of varnish can simply be placed in a mug of hot water, but the plate has to be slowly and evenly heated over an open flame – being sure the image side faces up so as to not burn off the image. Once they are both warm, the varnish is poured into the middle of the plate.

Pour just the right amount of varnish onto the plate. Too much and it will go everywhere resulting in a big mess, too little and you will leave spots of unvarnished areas.

Pour just the right amount of varnish onto the plate. Too much and it will go everywhere resulting in a big mess, too little and you will leave spots of unvarnished areas.

Allow the varnish to slowly fill the plate, you don’t want to force it too quickly to the edges or the varnish will pour off the sides, and likely all over your hands. The varnish and plate immediately begin cooling down, so the varnish flows much more slowly, and as the alcohol evaporates the varnish hardens. It has to be spread quickly but not in haste – a fine balance!

Work clockwise around the plate so the varnish fills each corner and part of the plate, ending with the corner nearest to you.

Work clockwise around the plate so the varnish fills each corner and part of the plate, ending with the corner nearest to you.

When the plate is nicely covered the excess varnish is poured off. The varnish is very sticky and messy so to keep it off our hands great care has to be taken, gently tilting the plate while balancing it on fingertips from beneath. Once the varnish stops dripping, you can dab off the edge and hold the plate by the corners.

Pouring off the excess varnish in to a small jar. This can later be filtered, to remove all dust particles, and used again.

Pouring off the excess varnish in to a small jar. This can later be filtered, to remove all dust particles, and used again.

The varnished plate now has to be dried. This can be a bit stressful as you are again warming your precious collodion image over an open flame, but this time your plate is also surrounded by vapours of alcohol. If you watch the flame closely you can see it wicking up to the plate following the trails of alcohol.

Heating an alcohol drenched plate over an open flame can be a bit tricky. But keeping a watchful eye on the flame and your plate will ensure all goes well.

Heating an alcohol drenched plate over an open flame can be a bit tricky. But keeping a watchful eye on the flame and your plate will ensure all goes well

First time varnishers sometimes panic a bit when they see their image fog up as it dries, but this is simply moisture condensing as the alcohol evaporates. If you do not continue to dry the plate thoroughly through this phase of the process it can result in a mottled and pockmarked varnish layer. Drying the plate evenly and letting the all the fog dissipate will give you a beautifully glossy image surface.

It is important to remember that the surface is still sticky and shouldn’t be touched or rested up against anything for at least a day.

Varnish layers can end up quite messy if not handled with care for the first day or so.

Varnish layers can end up quite messy if not handled with care for the first day or so.

We can keep conditions pretty clean nowadays. Barring a few minor imperfections, our varnish layer came out pretty well.

We can keep conditions pretty clean nowadays. Barring a few minor imperfections, our varnish layer came out pretty well.

Happily, all our plates were varnished without incident, and my flat had a lovely smell of lavender for days afterwards.

    Rachel Nordstrom and Eddie Martin

Note: All reference numbers in this blog are temporary photographic numbers [PHtempxxx] as they are still in the process of being digitised, rehoused and catalogued. Keep an eye on the blog or our photographic collection database for information when they will all be available online.

Special thanks to the Roger Watson at the Fox Talbot Museum for a loan of the varnishing materials and supplies from the workshop stores.

 

4 responses to “52 Weeks of Historical How-To’s, Week 50: How to Varnish a Collodion Plate

    • It is really the icing on the cake of making these sorts of images. Glad you enjoyed it. -RN

  1. The loving care with which you handle your material is impressive.

    Items that become part of your Special Collections are lucky ones.

    AM

    Anne Splingaerd Megowan Los Angeles, California

    On Thu, Oct 16, 2014 at 2:13 AM, Echoes from the Vault wrote:

    > St Andrews Special Collections posted: “Back in Week 15 of our > Historical How-To’s, we created some collodion wet plate negatives. It is > here that I must confess we did not actually finish the job. Any collodion > photographer of the Victorian or modern age would tell you that if you want > to keep”

    • Hi Anne, thanks again for your lovely comments. I think this is probably a good point to mention that I havent, nor do I plan to varnish any plates we have in the collections.
      These were contemporary plates made by Richard Jones this past year. Occasionally I have heard of people varnishing older plates but that doesn’t really fall in line with current conservation standards. So we will just take some really good scans of the scratched and unvarnished plates then pack them away nicely so no more damage comes to them.
      Thanks again for your comments,
      Rachel

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