Cleaning, Conservation, Restoration of Old Tapesteries and textiles

The Royal Manufacturers De Wit was founded in 1889.

Yvan Maes De Wit, the present director, represents the fourth generation of tapestry weavers and restorers.

>The Royal Manufacturers cleans, conserves and restores tapestries. Today, it is the leading tapestry restorer in the world for museums and one of the leading laboratories for private customers.

The international success of the Royal Manufacturers De Wit can be explained by:

  • -its experience unequalled that it has acquired by treating the most prestigious and delicate tapestries in the world
  • -its state to the art technology which has contributed to the progress in techniques for tapestry conservation
  • -its unique infrastructure which concentrates all the aspects relating to the treatment of antique tapestries within the same laboratory.

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The state-of-the-art-technology and the infrastructure of the Royal Manufacturers De Wit

The state-of-the-art-technology and the infrastructure

1 History of research and technical innovation at the Royal Manufacturers De Wit

Whether in the field of cleaning (by aerosol suction), conservation (conservation-integration technique), lining (on a specially designed table), hanging (multi-pulley suspension system), storage (system of galvanised steel tubes), the Royal Manufacturers De Wit is considered in many countries as the private laboratory which, these last 25 years, has most contributed to the progress of tapestry conservation techniques.

The Royal Manufacturers De Wit stays constantly at the cutting edge of research, offering its customers state-of-the-art technology which is highly recommended by the opinion leaders in the field.

1980 New conservation methods

-As early as 1980, the Royal Manufacturers De Wit was the first large private laboratory to use modern conservation techniques, renouncing the traditional "stitching techniques" commonly used at the time in all the other private workshops. These new techniques are based on using less intrusive and lighter methods, focusing on conservation (see list of publications: Gruuthuse Museum, Bruges, 1982).

From 1985, these new original techniques were used for the treatment of tapestries for the Monuments Historiques de France. In 1987, one of those restorations would be published by "The Getty Conservation Institute" in collaboration with the IRPA (Royal Institute for Art Heritage), Brussels (see list of publications).

1987 New lining system

- In 1987, the Royal Manufacturers De Wit perfected its new lining system on a table specially designed for that operation. This system considerably improved the harmlessness, the precision and the efficiency of the work of fastening the tapestry on its lining.

This lining system is nowadays also used by German laboratories, among which, for example, the Bayerisches Nationalmuseum in Munich. This system has also been deliberately selected for the lining treatment of some of the most prestigious sets in the world (including, for example, "The Story of David and Bathsheba" at the National Museum of the Renaissance in Ecouen castle).

1990 Conservation-integration system

- Since 1990, the Royal Manufacturers De Wit has improved its "conservation-integration" system, applying it to some of the most prestigious tapestries in the world ("Panos d'Oro" and "Los Honores" from the Patrimonio Nacional of Spain). In 1993, this system would be published in "Golden Weavings" and in 2000 in "Los Honores, tapestries woven for Charles V" (see list of publications).

1990-1995 New separate rooms for each specific treatment

From the early nineties, the Royal Manufacturers De Wit was the first laboratory to implement a policy of separate rooms specifically designed for each stage of the tapestry conservation process. This laboratory would be the first one having its own quarantine area for the treatment of dirty tapestries. The laboratory has also its own security room with aluminium tubes, a dark room and lastly a decontamination space.

1991 New system of cleaning with aerosol suction

In 1991, Yvan Maes De Wit registered a patent for a process of "cleaning of textiles by aerosol suction". This system would be very successful internationally and was very soon to become the only approved cleaning method in countries like Germany, The Netherlands, Switzerland, Austria and the Scandinavian countries, countries often considered as being at the cutting edge of textile conservation. This system would also be very successful in France, Italy, Spain, United Kingdom and the United States, where the largest collections entrusted their most valuable pieces to the Royal Manufacturers De Wit, generally without asking for competitive quotations (see list of references).

2005 New original hanging and raising system

- In 2005, Yvan Maes De Wit patented an original system for hanging and raising textiles. This system uses a specially designed batten with integrated pulleys and a security. This new system would be selected for the hanging of the most important series of tapestries (woven after 1400) conserved in France, the set of 10 tapestries of the "Story of David and Bathsheba" from the National Museum of the Renaissance at Ecouen Castle and a large number of other tapestries in Europe.

2005 New original process for the storage of textiles on galvanised steel tubes

- In 2005, Yvan Maes De Wit patented an original textile storage process using tubes made of galvanized steel wrapped in a sheath of polyethylene foam for the storage of textiles. This system was selected, with the agreement of the Laboratoire de Recherche des Monuments Historiques de France, for the reserve of Chambord castle and the reserve of the Angers castle two of the largest storage rooms for tapestries in France.

2 The cleaning of textiles by aerosol suction at the Royal Manufacturers De Wit

Method :

The textile is laid flat on a suction table. The suction applied to the fabric is constant and uninterrupted and keeps the tapestry in this position until cleaning and drying has been completed. A cloud of steam, to which a very small proportion of detergent has been added, is produced above the entire fabric and is sucked through it.

This system was patented in 1991.

Comparative advantages:

The comparative advantages arising from these exclusive features are:

1 Control of the risks of bleeding of unstable dyes

The bleeding of unstable dyes during washing is the nightmare of textile restorers. One of the decisive advantages of the aerosol suction cleaning method of the Royal Manufacturers De Wit is to prevent the lateral bleeding of unstable dyes. Over fifteen years' experience means that we can affirm that uninterrupted suction is one of the factors that makes it possible to achieve this exclusive result.

2 Reduction of mechanical stresses

The fact that the entire fabric is kept constantly in an immobilised position throughout the treatment process, ensures that mechanical stresses are reduced in an optimum way. It is difficult to imagine a gentler treatment than an aerosol mist being sucked through the entire surface of a fabric at the same time.

3 Control of the risks of irregular shrinkage and deformations and the recovery of the original shape

LMost old tapestries to be cleaned contain consolidation fabrics or reflect many interventions where more recent materials have been used. All those materials shrink in different ways subjecting the original fabric to opposing tensions and therefore to harmful deformation. As we have been able to confirm for over 15 years, only uninterrupted suction over the entire textile at the same time makes it possible to prevent irregular shrinkage and the ensuing undesirable deformations.

Another outstanding property of continuously working suction is that fabrics that have undergone previous deformation can recover their shape. Irregularities in the fabric can be flattened out when it is dry and immobilised, on the suction table, before cleaning begins. This latter operation together with drying enables the old fabric to recover its original configuration and to ensure that it retains that shape to a great extent.

Exceptionally short total treatment time – only 6 hours

A tapestry measuring 45 m² can be completely dried at 30° in two hours owing to the process of uninterrupted suction over the entire fabric at the same time. If we consider that average cleaning time lasts one hour and rinsing 2.5 hours, the whole cleaning process therefore requires less than 6 hours. Any risk of hydrolysis of fragile fibres is thereby averted and the entire treatment can be constantly supervised throughout a normal working day.

5 Unequalled safety and reliability

A whole range of means of inspection has been implemented to optimise the stringent monitoring and supervision of all the phases of the cleaning process (automatic sampling of water used and water extracted; automatic analysis of the temperature, pH, conductivity; graphic presentation of these parameters by computer with display of minimums, maximums and delta; high-definition moving and remote controlled camera with a zoom lens set for taking close-ups …).

The experience accumulated through the incident-free cleaning of more than 2,000 tapestries for over fifteen years means the Royal Manufacturers De Wit can offer its customers unequalled safety and reliability.

The conservation method of the Royal Manufacturers De Wit


Prior to any intervention on a gap, the adjacent fragile areas are stabilised on linen fabrics using a network of large and small vertical consolidation lines.

These two networks transfer the tractions of the weak areas to the adjacent strong areas and thereby stabilise the old fabric and ensure its mechanical cohesion. During a second phase, the actual gap is stabilised by a network of angled fixing stitches that follow the twist of the bare warp threads to create a mechanically stable and cohesive whole. This conservation method is based to a great extent on the technique developed by the IRPA (Royal Institute of Artistic Heritage), Brussels.

Comparative advantages:

1 A more logical and cohesive method

The methods of intervention of the Royal Manufacturers De Wit give priority not to the treatment of the actual gaps, which are areas where original materials are irremediably lost, but to the stabilisation of their surrounding area, where original materials in a critical situation can still be saved. This approach is diametrically opposed to the traditional "stitching" methods that focus on the treatment of the gaps at the expense of the threatened peripheral areas and thereby neglect the crucial problems of transfer of harmful tractions.

2 A clearer and more readable method

Any conservation intervention performed by the Royal Manufacturers De Wit is always recognisable and identifiable by an unspecialised third party. It is recognisable straightaway on the reverse of the tapestry by the fact that every intervention is always carried out on a consolidation fabric and is immediately identifiable. It is also recognisable on the front of the tapestry, since the consolidation stitches are different from the original weaving stitches, while being invisible at a normal viewing distance.

3 A more reversible method

All our fixing stitches are spaced out regularly and systematically from one another while minimising the intersections and thus optimising the reversibility of interventions.

As far as these three items are concerned, the comparative examination of the reverse of the tapestries treated by the Royal Manufacturers De Wit is no better way to convince any attentive curator or art connoisseur.

The visual integration method of the Royal Manufacturers De Wit


The visual integration of the gaps is only carried out at the Royal Manufacturers De Wit when the phase of mechanical consolidation of the fabric has been entirely completed. It is carried out while not interfering in any way, either with the previously performed consolidation work or with the adjacent original materials.

Comparative advantages:

1 Readability of the aesthetic treatment

The visual integration process of the Royal Manufacturers De Wit is always considered as optional, materially independent of the conservation work. The readability of such visual integration interventions is increased owing to the fact that the wefts used for this purpose are intentionally spaced out, making this treatment always recognisable at a short distance while blurring it at a normal viewing distance. This approach is clearly distinguishable from usual conservation treatments, where the same thread is used indissociably to provide mechanical stabilisation and aesthetic integration.

2 Double reversibility

By making a technical differentiation between the two basic aspects of conservation, the mechanical aspect and the aesthetic aspect, the conservation and aesthetic integration interventions become independently reversible. The entire methodology of interventions is modified in this way: the continued existence of the aesthetically neutral stabilisation interventions is ensured and the reversibility of the aesthetic interventions, inevitably subject to interpretations, is made easier.


The lining system of the Royal Manufacturers De Wit


The lining is laid flat on a very large table specially designed for this operation and the tapestry is unrolled on top of it and is therefore facing the restorer. The fabric and its lining are next slid over a system of slits through which the tapestry/lining can be fixed by the restorer in an accurate, effective and controlled way.

Comparative advantages:

1 Greater effectiveness owing to a much greater density of fixing stitches

Irrespective of the methodology, the effectiveness of a lining also directly depends on the number of fixing stitches. A lining from the Royal Manufacturers numbers more than 300 fixing stitches per m² whereas in France, for example, as well as in other countries, it is in the region of 130 stitches per m² or sometimes even less.

2 A higher quality material

The Royal Manufacturers De Wit uses exclusively very high quality pure linen (a Belgian speciality). It is very fine (24/24 threads/cm), extremely resistant and offers good resistance to air flow. It is washed twice at 90° and is then dyed ochre, which further reduces its residual shrinking potential.

3 A distinctly more accurate and more effective fixing method and one that is more harmless to ancient fabric

In a conventional lining process, the restorer faces the lining without any visual control to check whether his work is effective, harmless and invisible. He is also compelled to use curved needles. At the Royal Manufacturers De Wit, by using the described equipment, the tapestry is laid facing the restorer throughout the entire lining operation. The restorer is then able to use a fine straight needle to ensure that each fixing stitch is accurately underpinned by only one warp thread, the strong element of the old fabric, and to slide it invisibly between two weft threads. Lastly, he can check that each fixing stitch is supported by a sound element of the tapestry and thereby optimise his fixing process while preserving the fragile areas of the old fabric as best he possibly can.

The hanging and raising process of the Royal Manufacturers De Wit


The tapestry is raised in one piece using a system of ropes, an automatic rope locking system and lastly a system of special battens in which pulleys are integrated for equalising and reducing tensile stresses. This system is invisible when the tapestry is hung. It is patented.

Comparative advantages:

1 Safety of the tapestry when it is being raised or hung

This system makes it possible raise and hang tapestries more than 10 m long in one piece; the operation is carried out by two persons only, no particular effort is required and the hanging batten remains quite vertical and does not bend. Under these circumstances, the tapestry stays perfectly flat and is therefore not subjected to any unequal tensile stress. Optimum conditions are attained for the safety and preservation of the tapestry.

2 Safety of the handlers when the tapestry is being raised or hung

During the raising or hanging operation, the operators stand a certain distance away from the tapestry and are therefore protected from an accidental fall of the hanging batten caused by the breaking of wall attachments. This is all the more important since in many historic buildings, a secure wall attachment is not always certain to be found and surprises are to be expected.

3 Better long-term preservation of the old fabric

In this system, the fastening Velcro is sewn next to the old fabric on a 15-cm extension running alongside the lining. This original procedure:

- does away with the harmful long-term influence of acid Velcro strips on the old textile;

- avoids folds forming when large-sized tapestries are rolled on tubes. The build-up of excessive thicknesses of Velcro strips often results in the formation of harmful folds when the tapestry is rolled up. This consequence is avoided since the strips are placed next to the old fabric;

- means that worn Velcro strips can be more easily replaced in the future or be subsequently replaced by a more appropriate system.

4 Two variants of the system exist

In one of the variants, the rope locking system must be fixed in the wall about 2m off the ground. In the other, the locking system does not require any wall attachment and only needs to be fixed at the top of the tapestry:

- in both cases, all the components of the raising system are invisible;

- - in both cases, emergency release is easy and almost immediate.

The process for storing tissues on galvanised steel tubes of the Royal Manufacturers De Wit


The tube is composed of a galvanised steel sheet. The tube is fitted with strengthening caps made of the same metal at both ends. The main body of the tube is fitted with a polyethylene foam sheath cut out in such a way that the hanging system (Velcro for example) may be placed next to the foam sheath. This system is patented.

Comparative advantages:

1 A neutral and inert material, stable in time and uninflammable

Galvanised steel is used in many fields and in the worst weather conditions (piping, pedestrian elements, offshore pontoons in saltwater, anchors, etc.) owing to its very high resistance to corrosion. The Laboratoire de Recherche des Monuments Historiques de France (Research Laboratory) has fully agreed to its use for the very long-term storage of old textiles.

2 A self-supporting material very resistant to bending

As an example, on the tapestries of the series "The Story of David and Bathsheba" (approximately 40 m²), after the jolts caused by two lorry journeys, we noted a derisory bending of 5 mm on tubes 5.30 m long, supported only at their ends.

3 A light material easy to handle

As an example, a complete large-diameter tube (25 cm), 5.25 m long, weighs 26 kg, i.e. 13 kg for each carrier.

4 A tube fitted with a neutral sheath made of polyethylene foam

This foam is placed in such a way that fastening systems (Velcro or other) may be rolled up next to the polyethylene foam. This avoids folds being formed, caused by the build-up of excessive thicknesses of Velcro strips (or any other fastening system) when large-sized tapestries are being rolled up.

This system has been selected for the reserve of Chambord castle (75 tap.) and the reserve of the Angers castle (120 tap) two of the largest storage rooms for tapestries in France.

8 The other technical facilities and equipment available at the Royal Manufacturers De Wit

The Royal Manufacturers De Wit takes charge of all the aspects relating to the treatment of tapestries. It has unequalled facilities available for this purpose: separate rooms for dust removal, cleaning with water, decontamination, conservation, lining, dyeing, safety storage, photography, scientific analysis, each having the most advanced equipment.

1 Independent room for removing dust from tapestries before cleaning

Before being cleaned, the tapestries are treated in a separate room, assigned only to the purpose of treating dirty tapestries. This separation prevents any contamination of clean tapestries. The dust room has a treatment table more than 5 m long specially designed for vacuum cleaning tapestries and removing the lining. Furthermore, the glass table is illuminated from underneath for a better inspection of the fabric by transparency. This equipment means that the fabric is never folded and stays perfectly flat throughout all the operations. The room is equipped with a vacuum system, the central unit of which is located outside the room, so that dirt is immediately expelled away from the treatment areas. The suction pipes and brushes are suspended above the table for easier handling, without rubbing the old textile. The suction force can be finely adjusted and controlled by a vacuum gauge. During and after vacuum cleaning, the tapestries are handled exclusively on aluminium tubes.

2 Decontamination room

The Royal Manufacturers De Wit has a decontamination area in its cellars.

Decontamination is performed by freezing in a large-sized freezer.

3 Independent dyeing room

All the materials used in the treatment of tapestries are specially dyed in our dyeing room: silks, wools, linen consolidation fabrics and linen linings.

The Royal Manufacturers De Wit has a dyeing machine for this purpose, the parameters of which can be programmed by computer. This professional machine guarantees constant quality of treatment of raw materials. The dyes are exclusively high light resistance dyes used in three-colour processes.

Today, the availability of a self-contained, specialised dyeing laboratory is the only solution making it possible to offer our customers a quality guarantee over the long term. In actual fact, the professional textile dyeing sector is currently too focused on the short or the medium term to be still able to offer the long-term guarantees that we consider indispensable.

4 Main tapestry conservation treatment room

In this room (220 m²), ten looms, from 9 to 3 m wide are available.

The looms are all identical (except the one of 9 m) and designed according to the most stringent standards (adjustable in height and inclination, very wide work surfaces, movable lighting available for daylight or "yellow" light).

5 Safe room

The storeroom for the tapestries is a strong room with armour-plated walls. The entrance door is a safe door weighing 480 Kg. The storeroom contains 95 aluminium tubes for the storage of tapestries. Our safe storage room was used as model for building the storage rooms for the tapestries of Strasbourg Cathedral and the collection of the Monuments Historiques de France at Chambord Castle (75 tapestries).

6 Independent room for storing transport materials and crates

A storeroom of 80 m² with 60 m of racks ensures the conservation of the thousands of dyes we have in reserve. A special area zone is provided for storing the special crates designed for the transport of tapestries.

7 Photography room

A room of 8.6 x 12 m with walls completely covered by black curtains provides the ideal conditions for taking photographs of tapestries. This room is 5 m high and has an opening in the ceiling for taking photographs of tapestries that are not yet lined, laid flat before conservation treatment (front and reverse sides). These pictures can be taken in Ektachrome size 20 x 25 cm, 6 x 7 cm and 24 x 36mm (normal focus and macro, analogue and digital). After having published several reference books about tapestries, the Royal Manufacturers De Wit has acquired undeniable experience in making very high quality pictures of tapestries.

8 Computerized documentation centre

Yvan Maes De Wit is member of the Belgian Chamber of Art Experts (as a tapestry specialist). His assistants An Volckaert and Paul Michielssen, graduates in art history, also specialise in tapestries.

A specialised library and computerised databank are available at Royal Manufacturers De Wit for its iconographic and historical research. In the databank, all the pictures are digitised, described and indexed by computer according to many search keys. Over 14,000 tapestries are inventoried in the databank

9 General security

The rooms described above are all equipped with fire detection systems, surveillance cameras and intrusion detection systems connected to a central monitoring unit. The building, dating back to 1484 and recently restored, is protected by firewalls. A caretaker lives on the premises. A 4.5 m high surrounding wall encloses the building. The building and the safety equipment are approved by the most demanding insurance companies.