Tuesday, 23 April 2013

You've been framed!

Madonna and Child tablet conserved
but needing a frame for display.

Detail of moulding being carved

Making things that are curved can be interesting technical challenges. The Madonna and Child tablet that has undergone conservation works is for display at Temple Newsam House. Missing its frame, a new one, of an appropriate design for the 17th century, is being made in Temple Newsam's conservation department. Starting from the tablet a template was made, and then divided into four pieces. Oak was chosen for its strength and density; softwood would be easier to carve, but because the tablet is heavy, and softwood is also prone to some movement and splitting, this makes it less than ideal for framing the sort of object we are talking about here. It is also historically accurate, oak would likely have been used in this instance, and certainly all good church and cathedral joinery is done in oak. Four pieces of quarter sawn oak were rough shaped, and their ends precisely surfaced so that the ends met cleanly. Quarter sawn oak is very straight grained, and stable. The four pieces were glued together under the pressure of a web cramp. After the glue had set a floating tenon was let in across each of the four joints. Precisely shaping the inside and outside curves was the next step. This was followed by laying out with a sharp pencil the lines of the mouldings to be carved, the carving. This was done entirely with an old hacksaw blade that I ground to make a kind of planing knife. It worked surprisingly well, and the carving was quicker than I thought it would be. Keeping the edge sharp is essential, of course. So, regularly, it is over to the diamond grit lapping stone to get an edge back, and then giving the new edge a tickle on the polishing wheel. Wicked edge achieved! Over the coming days I will update with all the procedures, because eventually this frame will be watergilded, and then toned down to give the sort of appearance of an old gilded surface.

Frame in oak being fabricated and shaped.
With the moulding carved and smoothed the frame is ready
for the next stages.

Onto the bare oak a coat of rabbit skin glue size is brushed on. Mixed 1 part rabbit skin glue granules to 10 parts water, and then gently heated into solution. The subsequent layers of gesso is the size in the same dilution with chalk (calcium carbonate) mixed in. More about gesso and its purpose when we get to that stage. The hot size when applied to the oak will be absorbed a long way into the timber. This will prevent excess rabbit skin glue in the gesso being absorbed into the oak. This would weaken the gesso and make it crumbly. The size also helps with bonding the gesso to the wood, forming a chemical bridge between the two. Powerful hydrogen bonding takes place between the size and the wood, and the size and the gesso, an interface between the wood and the gesso, and absorbed into both.

Rabbit skin glue size being brushed and worked
into the surface of the wood that will be gilded.
Gesso is a mixture of the rabbit skin glue size and powdered chalk. Its purpose is to enable an extremely smooth surface, on the item being gilded, to be created. The binding medium, rabbit skin glue is also used in the subsequent layers, the bole, and the size water applied at the gilding stage. The size water activates the dry glue in the gesso and bole, and bonds the gold leaf down to the surface.

Powdered chalk is mixed into the
size to make gesso. Enough chalk is mixed in
until the gesso has the appearance and
consistency of single cream.

Several coats, at least 12, of gesso are applied to the substrate.
The coats should all be applied the same day to ensure the
layers bond properly.

After enough gesso has been built up it needs smoothing,
and re-capturing of the detail that has gotten a little clogged up
with gesso. This is done with abrasive papers. Also with "water-
polishing". Fine cotton cloth slightly dampened slightly
dissolves the surface and allows a little re-distribution and smoothing.

Application of bole is the next stage. Bole is made of rabbit
skin glue size, and very fine grain coloured clays. Here
the clay is being crushed and mixed with water before being
added to the size.

Here the clay and size have been mixed, filtered for smoothness
and is ready to apply, fairly hot.

 Several coats of bole are applied. Yellow colour bole, and red bole
on areas that will be burnished (more about that at the
application of gold leaf stage!).

The coats of bole are made extremely smooth with
a succession of abrasive papers, finishing with
an abrasive of at least 6000 grit. Effectively this
action is polishing the bole. The surfaces are now
ready to receive the gold leaf.

Gold leaf is extremely thin. In water gilding it is bonded to the substrate by the glue in the bole and the gesso. This is re-activated with water. To help bonding further a little rabbit skin glue size is added to the water. A little ethanol (a kind of alcohol) is added too. This helps to break the surface tension of the water and helps it to wet the surface instead of beading. Gilders call this solution "size water". The gold leaf is cut to manageable, suitable, sizes and shapes with a gilder's knife. The gold is supported on a gilder's cushion at this stage, having been drawn out of the book of gold leaf it was stored in. A gilder's tip is a kind of wide, fine brush. It is used to pick the gold up. It has to be slightly sticky so that the gold transfers to the tip. I put a little Vaseline on the back of my left hand, and periodically, when the gold no longer stays on the tip, brush the tip over the Vaseline.

Laying the gold leaf

Picking up gold leaf with a kind of brush called a gilder's tip

Size water is applied to the bole. This activates the glue
in the bole, and gesso. As the water is drawn into
the porous surface the gold leaf is sucked down onto
the surface, and is bonded by the glue.
All the gold leaf down. Next step, after the gilding has
dried, is to dust off the excess, and then burnish the
two round mouldings.

Some hours after applying the gold leaf the gesso reaches the right
moisture content for burnishing. The tool for this is a polished agate stone.
Gentle pressure compresses the gesso and gold, and brings about
a deep and lustrous shine.

The tablet has been offered into the frame's rebate. Two battens
are carefully shaped to the contours of the back of the tablet.
When fixed into place the battens apply no tension to the
tablet. Plaster behaves well under compression. The same cannot
be said for its being under tension!
The frame has been toned down with some coats of weak size
with black and brown watercolour mixed in. This is very effective
in giving an aged appearance, taking down the very bright, new gold
without detracting from its lustre. Ready for installation by
Temple Newsam's technicians. Fait accompli!

Posted by Ian Fraser

Thursday, 11 April 2013

Magic and Mystery Session at Leeds Museum Discovery Centre

This spring the Community History Team at Leeds Museums and Galleries are working with a Peer Support Group, and colleagues from the West Yorkshire Playhouse on the topic of Magic and Mystery. On Tuesday we took a quick look at the ritual practices in Tibet, as Tibetan religious art is famous for its use of human bone – usually the bone of respected priests and abbots, who have shown special spiritual powers during their life-times.  

A star item was this mounted skull cup, or Kapala, one of two in the collections (the other was shown in the recent Treasured exhibition at Leeds City Museum, see the detail on the poster). On this cup you can see the human cranium clearly, sitting on the triangular brass stand beneath the encased cover (whose handle knob is now missing). The cover is rather battered but you can still see deity images and key words in Lautsa script round the sides. The cup was found in a Bradford attic in 1962 and taken to Mr S Jackson at Bradford Museum, who gave it to a Mr K Wilson, in  Ilkley, to take in to Abbey House Museum.  It is amazingly similar to one at the British Museum http://goo.gl/UH2oO.
Mysterious in a different way is this masquerade set, supposedly from the Himalayas, purchased by the museum from Ye Olde Antique Shop, Denholme, in 1975. But if you look closely many aspects of these items reflect a more European style, possibly of New Age performance of belief.

The horned mask has a face made of green leather with red leather lips and a large tongue and gold leather teeth. The nose area seems to be made from a flattened a pierced metal implement, like a masher for vegetables, or a type of hoe for weeding. Large numbers of gilded beads are glued onto the face on the cheeks and forehead. The back of the head is made of red and black woollen fabric, woven and felted, with green wool hair attached. The two horns are of gilded wood and a small carved and gilded skull sits between them. Wire loops threaded with large wooden beads, glass beads and yellow wool tassels and pom-poms rise around the horns. Below the mask are four red velvet flaps which would cover the wearer's shoulder. They are trimmed with curled and coiled foil braid and modern costume jewellery that is clipped on (some of which does feel like marble, and is carved with roses in a Chinese style). The mask also came with a skirt or apron, a drum and a wand. The skirt is very European looking, and we have not been able to understand or translate the symbols on it. The drum is painted with a very European looking dragon, and some Chinese characters, and the wand has a crocodile head which looks as if it belonged to English pantomime.

We are not sure which character the mask represents, or which dance or performance it would have been worn for. The owner of the antique shop who sold the objects to us described the set as a 'Devil Dancer's Outfit'. Here is a link to a video of a cham dance from the Bon (pagan) faith http://goo.gl/Uamsd, if you want to compare this mask set from some modern versions in performance. It’s all very intriguing and if you have ever come across a similar mask set, do let us know.   

We also looked at other charm items, from Africa and a small modern charm necklace bought recently in Leeds. Here are some comments from the participants of the session when we asked them if they had their own personal charms.

June always carries a tiny horse’s head of gilt lead in her purse, she has had it for many decades – a gypsy sold it to her when she was 15. A tiny horseshoe was there too, but it dropped out. She also has a silver lucky charm bracelet, which belonged to her mother.

Trevor used his grandfather’s watch in every exam. It was a good time-keeper, as his grandad was a railway man. His mother had a small coffin with an image of someone laid out inside it. She kept it locked away in a box, and told Trevor that if the image inside ever came out of the coffin a close family member would die.

Maureen has a different charm in each window of her house, a crystal or a rainbow, a chime, all for a bit of feng shui.

By Antonia Lovelace and Sinny Cheung.

Thursday, 4 April 2013

A Romano-British Head Pot

Imagine my surprise when, whilst sorting through a box of Romano-British pottery sherds from Leeds Museums and Galleries collections, I found this handsome face staring (well, perhaps staring isn’t quite the right word) up at me!

This object (LEEDM.D.1966.0083), probably excavated from the Roman town of Aldborough in North Yorkshire, is a ceramic fragment which has been moulded in the form of a male face. You can distinctly see his nose, pursed lips, left cheek and a section of chin. This sherd would appear to originate from an elaborately decorated vessel - was I looking at the Roman equivalent of a Toby Jug?!

Vessels with faces on them seem to have been popular throughout the Roman Empire. The most common type are face pots, which were probably introduced to the province of Britannia by the Roman army during the first century AD, as early examples are found primarily at military sites. However, being seemingly fashionable and popular, this style of vessel soon spread throughout the province. The portraits on these however are much more schematic, and indeed more comedic, than our example.

A pair of typical Romano-British face pots, these examples were found in London (Braithwaite 1984: 109, fig. 6).

The more naturalistic, Classical features of our face suggest it originates from a different type of vessel, probably a small head pot. Similar faces are also found on Late Roman head-neck flagons (where a small moulded head is applied to the neck of the vessel), but I think our example is slightly too large for this.

Head pots consist of a moulded human head which forms the body of the vessel. They seem to be an insular British occurrence, developing quite independently from their distant cousin the face pot, and became fashionable in the early third century AD. They were made locally but influenced by the exotic cultures and styles of the Eastern Mediterranean. They are uniquely found on our island and their distribution is further confined to the east of the country, north of the Thames.

A selection of Romano-British head pots, these were found at York, Piercebridge and Chester-le-Street (Braithwaite 1984: 118, fig. 11).

The jury is still out regarding the function and use of these vessels. Although many examples lack context, the majority of provenanced head pots come from ritual sites, but a few have cropped up on domestic ones too. They are probably linked to some form of ritual or cult – but which, we do not know. One head pot found at Lincoln bore the painted inscription DON MERCVRIO – ‘To the God Mercury’ – but no other vessels have been found so usefully labelled. Compared to face pots which are usually coarse cooking ware, head pots are relatively fine. Perhaps they held liquids rather than food, such as wine for libations and offerings.

So what role did the faces play in all this? Did they have an important ritualistic function, or are they purely decorative? Whilst some similarities have been found between faces on different pots, the majority of portraits vary greatly, suggesting them not to be associated with one particular deity or cultic figure. Is the face depicted on our vessel that of a specific individual, a deity or just a generic portrait? Such objects pose interesting, and indeed frustrating, questions and serve as a reminder of how some aspects of the past still remain elusive to us.

Interested in reading more about these fascinating Romano-British vessels? This article provides an excellent overview of the subject: Braithwaite, G. (1984) ‘Romano-British Face Pots and Head Pots’, Britannia 15, pp. 99 – 131.

Lucy Creighton