Conservation of Cragside’s Chenille Carpet

This last Spring we finished and returned a large 6 x 9m chenille carpet from Cragside House in Northumberland. The carpet has recently been relaid and newly commision eyemats installed to replace the old druggets – see Cragside’s blog.

This series of posts is from our bulletins throughout the project to the property and show some of the challenges we faced with such a large object.

Bulletin 1. Conservation of the Dining Room Carpet – Cleaning

The Cragside dining room carpet is a Chenille wool faced carpet possibly manufactured by Templetons around 1870-80 specifically for the room. It is an Axminster construction with a wool warp and weft foundation, with jute stuffer yarns. The top layer of wool chenille which forms the pile is held in place with additional cotton catcher warps.

IMG_0145Chenille carpet in the dining room- Cragside House

In February 2013 a condition assessment and treatment estimate was undertaken on the chenille carpet. After initial tests it was decided that a full conservation treatment of surface cleaning, wet cleaning and conservation stitching would be possible. It had originally been hoped that conservation work would take place in situ, onsite, but this proved to be very difficult and so the carpet was transported to the Textile Conservation Studio at Blickling.

In February 2014 a week was spent onsite at Cragside to surface clean the carpet and roll it in preparation for transportation to the Studio.

IMG_0151Vacuuming each square metre with a Miele vacuum cleaner and large flat head tool attachment at 90mb suction for 16 minutes.

Stages of work onsite included:

  • The carpet was gridded out into 1 metre square
  • Each square metre of carpet was carefully brushed with a soft rubber brush to remove lint and fluff from the surface of the pile.
  • Miele vacuum cleaners were used with the large flat head tool attachment at 90mb suction for 16 minutes per metre square section.
  • Where possible webbing patches adhered to the reverse of the carpet were removed.
  • The carpet was then rolled and at the same time the reverse was vacuumed at 90mb suction.

The carpet arrived at the Studio on Wednesday 5th March. Working in conjunction with Glyn Charnock of the National Carpet Cleaners Association, tests were undertaken to identify cleaning methods and equipment which would be effective whilst preventing damage both during and after the clean. In particular, the jute stuffer yarns were of concern as they are brittle and very sensitive to moisture.

IMG_0719The carpet arriving in the studio

Although the carpet had been meticulously vacuumed whilst onsite, there was still an amount of gritty deposits deep within the pile of the carpet. Gritty dirt can be quite problematic, wearing away at the structure of the carpet over time.

Tamping or back beating the carpet with latex paddles is the usual way to deep clean gritty deposits from carpets, but as this carpet measures almost 6 x 9 meters a less labour intensive method was developed using a rotary beater bar vacuum cleaner and a piece of sacrificial carpet.

The method used for tamping:

  • The chenille carpet was laid face down on the studio floor.
  • A sacrificial carpet was placed face up on top.
  • The pile of the sacrificial carpet was vacuumed using a rotary beater bar vacuum  vibration causes grit / dust to fall from historic carpet below.
  • The chenille carpet was lifted and debris vacuumed up each time (a new bag was used & kept to weigh debris.)
  • The process was repeated as necessary.
  • Finally the front was vacuumed again and the pile groomed.

The wet cleaning method developed was a combination of studio manager Ksynia Marko and Glyn Charnock’s experience, knowledge of products and equipment. Dehypon, a conservation grade detergent, was chosen for its desirable characteristics and low working temperature in conjunction with an industrial application using an upholstery extraction tool which had provision for variable water flow rate application.

Once fully dry, each metre square was then vacuumed again for 5 minutes to remove loosened particles of grit, as seen under the microscope after testing.
The cleaning method was very successful at removing the soiling and grit from the carpet. The carpet now looks considerably cleaner and the colours brighter. The flattened pile of the carpet has been lifted and it now has a rich and luxurious appearance.
Following on from the cleaning, testing will be undertaken to find a suitable solvent to remove historic adhesive from the reverse of the carpet before attaching a new linen tape. Then conservation stitching will commence.

Reception of an Embassy rehung.

Re-hangingAfter full conservation treatment at our conservation studio, the Reception of an Embassy tapestry is now back hanging in the Ballroom of Powis Castle.

Property staff using the hoist mechanism to rehang the tapestry.Property staff using a hoist mechanism to rehang the tapestry.

If you are in the area, please do go and take a look or if you would like to know a bit more about this tapestry take a look at The National Trust’s Collections online information here.

Reception of an Embassy – Bulletin 4

Continuing on from earlier posts about the conservation work we undertook on the Reception of an Embassy tapestry from Powis Castle here is the fourth in a series of bulletins we sent to the property. This bulletin dates from June 2014.

The relative silence from the Studio has been due to us tackling the challenging vertical cut that ran through the whole length of the tapestry.  This cut had been crudely re-stitched and was coming apart so conservation was necessary for aesthetic and structural reasons.

I have just calculated that based on 5½ warps per cm and a total height of 370cm that we inserted over 2,000 warps.  This section took us 360 hours to stitch, by far the longest in the whole tapestry.

All the new warps inserted across the long vertical cut which runs the full height of the tapestry © National Trust Textile Conservation Studio

All the new warps inserted across the long vertical cut which runs the full height of the tapestry.

Once all the new warps were in place we could begin to stitch them in place with brick couching in stranded cottons and wools to match the missing weft.  In some areas there was loose original weft still remaining.  In these areas the warps were woven in and out of the weft to mimic the original weaving technique. 007

Detail showing the failed stitching along the vertical cut.  

IMG_1478

Detail showing the warps inserted across the vertical cut.

The vertical cut went through the Latin inscription ‘EX FERRO/FI(V)NT/QVE/DVRATVRA/PER EVVM’, which translates as ‘out of iron come things that will last forever’, on the banner over the striped doorway and a letter was missing.  This was the letter ‘V’ in FIVNT.  In order to replace the letter a tracing was taken of another letter ‘V’ in the inscription onto Melinex, a clear polyester sheet.  This tracing was used to determine the positioning of the couching stitches that would make up the missing letter.IMG_1573

 New warps have been inserted across the vertical cut and a tracing of existing letters made to fill in the missing letters.

 IMG_1587

 Part way through couching with cream and dark brown wool to recreate the missing letters. IMG_2586 The missing letters filled in.

The other major challenge that we have faced in the second half of the tapestry has been some of the crude re-weaving that has been carried out in the dark brown wool areas.

The dark brown wool weft is particularly vulnerable to degradation due to the iron salts that were used to mordant (fix) the dyes originally.  These iron salts accelerate the degradation of the wool fibres with the result that the dark brown wools are often lost.

In the Powis tapestry the re-weaving has been crudely executed in a yarn which is black rather than dark brown to match the original.  A small sample of the re-weaving yarn was taken from the reverse of the tapestry and examined under a microscope to determine what type of fibre it was – it proved to be 100% acrylic!  Having said this the re-weaving was very extensive, so in areas where it had been reasonably well executed the decision was made to leave it in place, blending in any further weak areas with new brick couching in wool.  In the areas where it was very crude, causing distortions and the black colour was visually disturbing the decision was made to remove it.  The decision as to which areas to leave and which to remove was made at the outset of the treatment with the whole tapestry laid out so that specific areas could be examined against the overall effect.

The striped archway once the crude acrylic re-weaving had been removed and replaced with dark brown wool brick couching.

 The final five sections of the tapestry are in better condition, so we are feeling like we are on the homeward straight now.  The next job is to order the weaving of some new brown galloons with which to edge the tapestry.  When the tapestry was taken down for conservation it had a blue linen fabric edging all four sides, when this was removed the original dark brown galloons were revealed on the two side edges.  The decision was made to have new galloons woven for all four sides to give a crisp outline to the whole tapestry.  The original side galloons will be protected beneath the new replacement ones.

The tapestry will then be lined with down proof cotton cambric to protect the conservation stitching and to reduce the movement of air through the tapestry and consequently the soiling.  We currently propose to re-use the popper tape to re-hang the tapestry from as it is in good condition.

Reception of an Embassy – Bulletin 3

Continuing on from earlier posts about the conservation work we undertook on the Reception of an Embassy tapestry from Powis Castle here is the third in a series of bulletins we sent to the property. This bulletin dates from January 2014.Tapestry being worked on in the studio © National Trust Textile Conservation Studio

The tapestry is mounted onto a frame and stitched onto a support of linen scrim. The conservation stitching provides a combination of strength and support by evenly attaching the tapestry to the linen support fabric and an aesthetic reintegration of missing areas of design.

An area of previous crude repair which was unpicked, new warps were inserted and then couched down with coloured wools to match the missing wefts. By removing these visually distracting repairs the original weaving can be read more readily.

The shoulder and face of this figure have had a previous repair which has been crudely executed in unsympathetic yarns and colours. The repair was removed, new warps were inserted across the hole, then couched down through to the linen support fabric with wool and stranded cottons in the correct colours. This conservation stitching gives a more accurate impression of the original design. The aim with tapestry conservation is that when the tapestry is viewed overall the original design should be harmonious and able to be read, but when the tapestry is viewed close to it should be possible to see which elements of the weaving are original and those that are repairs. The spaced couching over one warp and under the next uses the same principle as the original weaving, but is carried out through a support fabric so that it is possible to easily identify it as a repair.

The work on the tapestry is progressing well and we have completed ten out of 26 sections. As well as dealing with the inherent weaknesses in the tapestry, for example failing horizontal slits and degrading dark brown wool and cream silk at some point in its history the tapestry has been cut up into quarters and then re-joined. The top left hand quarter has obviously been exposed to more agents of deterioration during its life as it has several bleached stains and completely missing areas. It is not known what has caused this damage, but in the bleached areas the wool warps and weft are very brittle and there are completely missing areas. In some of the missing areas it is not possible to know exactly was the missing design was so the decision was made to in-fill the hole with a dyed fabric patch. A specially woven ribbed fabric was used to imitate the tapestry weave to give the correct texture.

The next few sections of tapestry that we are moving onto are less damaged and their conservation will be more straight-forward; before we face the challenge of the vertical cut that runs the whole width of the tapestry.

Reception of an Embassy – Bulletin 2

Continuing on from an earlier post about the conservation work we undertook on the Reception of an Embassy tapestry from Powis Castle here is the second in a series of bulletins we sent to the property. This post dates from October 2013.

While the tapestry is at the De Wit workshops for wet cleaning there is also the opportunity to take high resolution photographs of the front and reverse after wet cleaning using the workshop’s photographic studio.

The front of the Powis Castle 'Embassy' tapestry. ©National Trust/Rachel LangleyReverse side of a tapestry depicting the reception of an embassy, wool and silk, southern Netherlands or northern France, c. 1545, at Powis Castle, inv. no. 1181082.The contrast between the faded front and the original colours on the reverse enables one to imagine how rich and colourful the tapestry would have been when first woven. Unfortunately there is nothing that can be done to restore the original colours as the dye molecules have been permanently altered by exposure to light. This is why the National Trust limits the levels of light to which their sensitive collections are exposed.

What the wet cleaning has been able to do is to lessen the harsh staining and make the whole tapestry visually more harmonious. Before cleaning, the upper left-hand quarter was significantly more soiled and stained than the rest of the tapestry.

The conservation treatment will involve applying a backing of linen scrim to the reverse of the tapestry and the conservation stitching, which will support and re-integrate missing areas of design, is carried out through this linen backing.

Once the cleaned tapestry was delivered back to the Studio it was mounted onto a wooden frame with three rollers to allow the attachment of the linen support. The linen support is rolled on the middle roller and is attached to the tapestry every 21cm across its width.

For estimating purposes the tapestry was marked into 21cm sections. As we work through the tapestry we can keep track of the actual time taken versus the estimated time.

During the weaving process where there is a change in colour and to create design features, slits are formed in the weaving. These are originally stitched together using linen threads. Over time this linen thread degrades and fails. In some areas the linen slit stitches have been replaced with crude stitching in unsympathetic colours. Where the slit stitches are original they are reinforced by stitching over them with a cotton covered polyester thread. Where there are unsightly repairs these are removed and replaced with the cotton covered polyester thread in a toning colour.

Before starting work on the tapestry it was necessary to dye some yarns. Wherever possible we will use commercially dyed yarns if the colour and the light fastness are suitable, however, one supplier has stopped producing one of the yarns that we used to use. Sometimes it is just not possible to find the correct colour and thickness so yarns have to be specially dyed in house.

In the Studio we use Ciba Giegy chemical dyes, even though the dyes used in the original tapestry are natural dyes. The reason for this is that the original natural dyes have already done the majority of their fading, as can be seen from the comparison of the front and the reverse, and we will match the faded colour with a stable chemical dye. If we were to use natural dyes for the repair yarns these would fade and more rapidly than the original faded natural dyes and cease to blend in.

IMG_3454aAs mentioned previously the dark brown wool weft is particularly vulnerable to degradation due to the iron salts used to mordant the dye. As a consequence large areas of the dark brown wool are missing and sparse. Some of the missing areas have been rewoven. This has been done rather crudely and with an unsympathetic yarn which, when a fibre sample was examined under the microscope was found to be acrylic. As this reweaving is so extensive it will not be possible to remove all of it, but discrete areas where it is practical will be removed and replaced with brick couching over the warps in dark brown wool. The photographs below show one of the faces where the definition has been re-introduced by couching in the pupils of the eyes and other features and some of the especially crude re-weaving in his hat has been removed and replaced.

In areas where the silk weft is missing or weak we couch the exposed warps using commercially available stranded cottons. The cotton has a lustre that is comparable with that of aged silk and it is available in a wide range of colours that can be blended to match the subtleties of the original silk weft.

The conservation stitching is progressing well and we are almost a quarter of the way through the tapestry.