Tapestry conservation is a long process – from the initial estimate and bids for funding to the final redisplay can take many years.
We are on the final leg of the Powis Castle ‘Reception of an Embassy’ tapestry and I thought I would share with you our bulletin updates to the property. These give you an insight into some of the work that has been completed and the challenges we have faced.
|Bulletin 1 – Conservation of ‘The Reception of an Embassy’|
Initially the tapestry was surveyed and an estimate for its conservation prepared whilst it was still on display at Powis Castle.
For ease of estimating at the Studio we have made a grid which we can lay onto the tapestry which marks the tapestry into 20cm sections. In this way we can judge the level of damage in each section and make an estimate of how long the conservation will take based on previous tapestries worked on with similar levels of damage. In photograph 1 a conservator can be seen laying the grid over the tapestry as it lies on the ballroom floor.
The tapestry was delivered to the Textile Studio in May 2013. Our first task was to record the condition of the tapestry before any treatment and have a professional photographs taken.
This tapestry has several problems as it has been worked on extensively in the past. At some point during its history it has been cut into four quarters with a horizontal and a vertical cut. The top left-hand quarter is considerably more soiled than the rest of the tapestry with general overall soiling and harsh tide marks from water staining. These four quarters have since been re-joined and the tapestry was displayed as a complete hanging.
One problem that tapestries commonly suffer from is the loss of the dark brown wool wefts. This is due to the iron salts which were used to mordant (fix) the dyes, these iron salts speed up the degradation process of the wool making it brittle and prone to loss. There has been extensive loss of the dark brown weft in this tapestry which has been replaced by re-weaving. On the whole, when viewed from a distance this re-weaving is not visually disturbing and is sound and will therefore be left in place. In some areas it has been rather crudely executed and appears rather heavy-handed; in these areas it will be removed and replaced with closely spaced couching over alternate warps to support the tapestry and give a more sympathetic colour in-fill.
Before the tapestry can be given its stitched support it needs to be washed. There were several challenges involved with washing this piece. One was to remove the heavier soiling and staining from the top left hand corner so that the whole tapestry has a more harmonious appearance and the second is all the re-weaving in the dark brown wool weft, very often the dyes in the re-weaving prove to be fugitive during wet cleaning.
In preparation for wet cleaned the heavy linen/hessian lining has to be stripped off. A lot of the previous repairs had been worked through this lining so they had to be cut in order to release the lining. The vertical and horizontal joins where left stitched together and the lining cut back.
The dyes used in the original are generally fast during washing although later repairs can be fugitive. Samples of all the wool yarns used in the re-weaving were tested and these all proved to be wet fast although a dark navy linen thread used extensively to re-stitch slits bled dye when tested. It was therefore necessary to remove this thread before wet cleaning.
The Studio has a long standing relationship with a workshop in Mechelen, Belgium which has a specialised wet cleaning facility. The unique features of this facility are that the tapestry can lie flat on a perforated metal base, through which an aerosol of water and detergent can be sucked. This is normally sufficient to release the soiling but with more heavily soiled tapestries additional sponging by hand is carried out.
Due to the specific issues with wet cleaning this tapestry the Textile Conservator went over to Mechelen to oversee the wet cleaning; in consultation with the Director of the workshop it was decided to wash the tapestry at a slightly lower pH as this would inhibit any potential dye bleeding of the repair threads. During the wash process the top left hand corner was give extra sponging and soft brushes were used to reduce the soiling and staining.
The results of the wet cleaning were very successful, although it was not possible to remove the staining completely it is very much reduced and the appearance of the whole tapestry is much more harmonious.
Following the wet cleaning in Mechelen the tapestry was transported back to the Studio for the stitched conservation.