Boeijink, Boekel, Van der Knaap Painting conservation studio
Paintlayer and groundlayer problems
Restoration and conservation

When we plan a restoration or conservation we always take the art object as a starting point. What has happened to it? What measures can be taken without harming its intrinsic value? Naturally we take into account the specific wishes of the client and what's possible from a financial point of view, everything in accordance with the solutions we can offer. We have a great deal of experience in working for private individuals, museums and other institutions. We handle paintings (on canvas, panel, metal, glass, etc.), polychrome objects, wall paper, draperies and banners.
Painting, oil on canvas, condition: after restoration
oilpaint on canvas
     Painting, oil on panel, condition: after restoration
     oilpaint on panel
Painting, tempera on canvas, condition: after restoration
tempera on canvas
Painting, oil on linnen support, Condition: during conservation
oilpaint on canvas
         Painting, oilpaint on cotton support, condition: after restoration
         oilpaint on cotton
Painting, oilpaint on marouflage (linen on panel).
Condition: during conservation
oilpaint on marouflage
Painting, oilpaint on paper on panel, condition: before restoration
oilpaint on paper on panel
Painting, oilpaint on wax-resin lining support.
Conditon: before restoration
oilpaint on lining support
Painting, oilpaint on panel, Condition: after restoration
oilpaint on panel
Painting on copper, condition: before conservation and restoration
painting on copper
Painting on banner, condition: before conservation
painting on banner
Painted sea chest, condition: before conservation
painted sea chest
Acrylic paint on vinyl, condition: after restoration
acrylic paint on vinyl
Painted metal clock face, iron and lead, condition: before conservation and restoration
painted metal clock face
Polychrome wooden sculpture, condition: after conservation and during restoration
polychrome object
Painted fan, condition: before conservation treatment
painted fan
Gouache on cardboard, condition: after conservation and restoration
gouache on cardboard
Ten Commandments (sign), wooden panel, condition: before conservation and restoration
Ten Commandments
Painting on glass, condition: before conservation
painting on glass
Panoramic wall hanging, oilpaint on relined canvas, condition: after conservation and restoration
panoramic wall hanging
Balinese painting, cotton, condition: before conservation
Balinese painting

After having studied the state of the art object(s) we discuss what's best to be done. Several options may be possible:
  1. Treatment is not really necessary. No charges.
  2. Minor treatment is advisable. An estimate is made of the charges involved.
  3. A quote is given in writing, consisting of a detailed description of the object, a proposal for treatment and an estimate. In this quote we make a distinction between:
    1. Conservation (necessary treatment in order to prevent further deterioration).
    2. Conservation and rendering presentable (necessary treatment with additional touch-up work on areas that disturb the essence of the picture).
    3. Restoration (taking every action necessary to render the object in a condition previously defined).

    Each of these options are accompanied by an estimate of charges.

Proposals for treatment can be singular example (Dutch) or retaining several options example (Dutch), according to the complexity of the treatment. A comprehensive proposal of treatment consists of several proposals varying from the most simple (the bare necessity) to an elaborate, complete treatment.
After reception of the signed commission we can start the treatment, every stage of which will be fully described and documented.
This report is presented to the client together with photo's of the situation of the object throughout the treatment.
If commission is granted, no extra charges are involved for the quote.

If there is no commission the client will be charged with a fee for the written proposal of treatment.
All bills include 21% V.A.T.
The client will receive a signed receipt.
The client will have to take care of insurance of the object during transport and accomodation in our workshop.
Simple treatment, oilpaint on canvas, condition: during removing dirt from the surface
1. simple treatment
Complex treatment, egg tempera and oilpaint on wooden panel, condition: after conservation and during restoration
2. complex treatment
The simplest treatment (photo 1) is a removal of surface dirt. The treatment will take several hours.
The complex treatment (photo 2) shows a detail of a painting after yellowed varnish and darkened retouchings have been removed and before the filling and retouchings of gaps and the application of a new layer of varnish has taken place. The time of treatment will be several weeks.

There can be anything wrong with a painting, ranging from simple damages to serious corrosion. A distinction has to be made between damages that were inflicted unintentionally, and changes made because they were the artist's choice.
As conservators we are of the opinion that preservation of the work of art is most important. That's why the halting of a process of deterioration and the protection against future decay is considered of utmost importance.
Why would one touch up damages in the paintlayer in the knowledge that the panel is being destroyed by woodworm? This may seem an extreme example that could well be our everyday reality if we did not give preferance to preservation.
Explanation of problems with layers of varnish, paint and primers
Blisters and flaking paint caused by shrinkage of the wooden panel
blisters and flaking paint
peeling of the paint by humidity, oak wooden panel
peeling of the paint by humidity
Torn linen of oilpainting
torn linen
Damage caused by woodworm in strecher bar of painting
damage caused by woodworm

We will describe to you what can happen to paintings, and what can and cannot be done about them, illustrated by photo's.

First there are the normal processes of aging, causing cracks in the paintwork, and increasing transparency of paintlayers. There may be changes in the structure of paint caused by techniques or materials used by the artist, for example wrinkling of the paintlayer. These symptoms should be accepted as characteristic of an older work of art.

One of the common treatments consists of the removal of surface dirt and/or the layer of varnish. The painting has lost its clarity and seems yellower than it used to be. The varnish may have yellowed or a deposit of grime and nicotine may have built up on the varnish, possibly a combination of these two.
The removal of surface dirt is simpler and less complicated than the removal of the varnish, so the costs will differ.
Removal of yellowed varnish from painting with solvents, canvas
removal of varnish with solvents
mechanical removal of varnish from paintlayer, panel
mechanical removal of varnish
Paining on canvas, removal of surface dirt (nicotine from cigarette smoke) from varnish
removal of surface dirt (nicotine)
Removal of surface dirt from the painted surface of a copper panel
removal of surface dirt
Then there is a possibility of mechanical damages, ranging from a small scratch in the varnish to heavy damages like the tear in the painting with the windmill (above). This type of damage comes under preservation: the longer one waits, the more serious will the deformity become, and the more difficult the treatment. A scratch in the paint or varnish is not a matter of preservation, but an esthetic treatment.
scratch on head top left, copper panel
scratch on head top left
Damage to the edge of the painting caused by the picture frame
damages caused by the picture frame
oilpainting, dent mark in linen canvas
dent mark
Steel nail through panel
nail through panel
Previous restorations can bring along the necessity of preservation. Restorations that were either badly executed or involving obsolete techniques can bring damage to the original. In such cases preservative treatment is necessary.
Old retouchings can have changed colour for several reasons. Sometimes the retouching have been badly done, the color and structure have integrated poorly, or paint has been applied on top of the original paint layer.
Old patches applied to the back to cover up holes and tears will in time cause deformations on the original linen; they will become visible on the front.
Materials used in restoration have to be reversible, i.e. the materials should not damage the original and must be removable with simple means.
Oilpainting with badly integrated retouching
badly integrated retouching
whitened retouchings (blanching) on oilpaint caused by light
whitened retouchings (blanching)
Wax patch on backside of painting during removal
wax patch
Boat varnish, oil based varnish on oilpainting
"boat varnish"
Adhesive plasters on backside of the painting to repair tears and holes
"adhesive plasters"
Repainting of a red beard with darker paint on a 17th century panel painting
repainting of beard
Cotton wool remains left by a varnish removal in the past
cotton wool remains
Varnish penetrating to the canvas through cracks in the paint and ground layers
varnish in canvas
Cradling can deform the original support (paint particles can flake), oilpaint on panel Jan van Goyen
cradling can deform the original support (paint particles can flake)
Undulating deformation due to cradling
undulating deformation due to cradling
Conservation studio
Tingietersweg 87
2031 ER Haarlem

T. +31 (0)23 5514993

Location/route »

Social Media

The painting conservation studio on Facebook  The painting conservation studio on Instagram  The painting conservation studio on LinkedIn