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Neighbour Plane trees in need - August 2024


In our immediate neighbourhood, 11 magnificent plane trees, which are between 50-70 years old, grow in a car park, the Kaasmarkt, in Leiden. Eduard Groen (Bomenbond Rijnland) and me tagged 2 of them in April, see experience below.

The city has plans to make this square green and minimise the number of cars. Another plan is, that the pavement, which has become bumpy due to the roots of the trees, is to be levelled again. The two plans could have been combined.


But on Monday, 19 August 2024, construction work began on levelling the paving - and with it the removal of many, even thick roots of these plane trees. Unfortunately, it will be a few years before we can say what this means for the trees.


They are doing their best to grow old in this spot - and are growing against all odds: Like the hardened stony ground, leaving the roots with too little oxygen and nourishment, which you can see from the aerial roots (last picture) all around each of the 11 trees. They filter car exhaust fumes from the air every day. They cope with heat and too little/too much water.


Trees provide us with essential ecosystem services (clean air, cooling the urban climate by up to 15-20 degrees in their shade, they form a healthy environment for free) and can only do this to an extent that is relevant to humans from around the age of 30.


Hopefully inhabitants of Leiden will be able to enjoy these wonderful green, quiet neighbours for decades to come.

 

Find here more information.

Best overview: Article Bomenbond Rijnland

Questions from Partij voor de dieren to the city council

Article Sleutelstad

Article Leidsch dagblad

Treetagging April 2024


Treetags are posters that can be used to give trees a voice.


They show some of the ecosystem services provided by a tree: how much water it absorbs, how much particulate matter, how much CO2 and how much oxygen it produces. Lisanne ordered these Treetags from PiusFlorius in March and, together with Eduard Groen (Bomenbond Rijnland), attached them to 3 trees in Leiden; two plane tree at the Kaasmarkt and one Wingnut tree in front of her house.


It's so nice to see how many people stop and read in front of it.


The local television Sleutelstad made a little film with Eduard and Lisanne (here pdf)


Engraving

Together with Laurien van der Werff, Lisanne tried to uncover the secret of copperplate engraving at the beginning of December with some engraving burins purchased from Polymetaal. We failed miserably - with admiration and immense respect for the masters of this technique from past centuries. And a very enjoyable afternoon together, which will surely be followed by more!


The last photo (4 written on it) shows the print further processed copper plate of the tree with the burin that Lisanne had drawn with sulphur.


Result: finding someone to teach us. Maybe Ad Stijnman?










Sulphur etching

Another experiment day together with Marten Hazelaar! This time we tried out sulphur etching. It's very simple: you mix sulphur and oil to make a paste that can be applied to the metal plate with a brush. Then you wait. The result:

  • It only works with copper. Leave on for as long as possible, at least 30 minutes.
  • Zinc does not work.
  • It is best to place the plates on a hot plate, then the metal reacts better with the sulphur.


Result: Not particularly satisfactory, better to achieve shading with aquatint. For continuation see next experience: Engraving.

In the garden

Burkhardt has used this summer to capture the colourfulness of his and Manuela's garden in small oil paintings. He has set up his easel on a piece in the middle of the lawn and left everything standing even in (rare) heavy rain.


With his ‘colour syntheses’, as he calls them, he uses colour not only according to its values, but also in its materiality.


Thus, the flickering of the summer garden becomes vividly and haptically visible in many light-filled colour explosions.


To the artwork






Sugar lift technique

In cold December 2022 we experimented with sugar lift technique, again together with Marten Hazelaar. For this, Marten brought a

-         mixture of 2 tablespoons of sugar dissolved in 50 ml of warm water.


We degreased the zinc plates with water, washing-up liquid and finally alcohol. Then we drew directly on the plate with the sugar ink. This has to dry, after which it is covered thinly with a asphalt-based masking varnish (from Charbonnel).

When everything is dry, we put the plates in a sturdy plastic tub and pour hot (80 degrees) water over them. Gradually, the sugar ink 'blasts off' the top coat where we drew with the ink.


Exposed in this way, the plate comes into the acid, in our case iron (II) chloride, 40%.

We have already achieved great results after 5 minutes.



Important:

-         Room temperature about 19-20 degrees / the acid must also have this temperature, then it works perfectly

-         The covering lacquer should be applied as thinly as possible. It should also be nice fluid (if necessary, warm it up in a water bath beforehand) and – if necessary – stretch it with a little benzine (Waschbenzin).

-         The lines of the ink can also be carefully removed with a pen during the water.

Marten´s Colours


In November 2022, Marten Hazelaar (artist in Delft) gave a workshop on two-colour prints and vaseline aquatint in our studio. In addition, we etched with copper sulphate in the studio for the first time, which is much more practical for observing the etching process, as it is transparent.


Marten also taught chine-collé printing, where a skin-thin piece of (japanese or chinese) paper is glued between the printing paper and the plate, with glue that dries transparent (rice or potato). A more detailed discussion follows here.


Many thanks to Marten, it was fun and instructive for all - and will be continued!


Dutch Mordant - Holländisches Bad


Together with the graphic artist Marten Hazelaar, Burkhardt and I wanted to try out the results that can be achieved with the Dutch mordant and whether it is worth working with it compared to nitric acid or ferric acid.

For the production, potassium chlorate is mixed with hydrochloric acid and water - in different parts depending on the recipe. We used 2 gr parts potassium chlorate, 40 gr hydrochloric acid and 60 gr water and made a bath for each zinc and copper.

It was interesting that gasbubbles formed with zinc and copper and and it smelled a lot like a swimming pool. Which is an indicator of chlorine gas.


This is hardly described clearly in the literature. Only S. W. Hayter (New ways of gravure, 1966) describes that gas formation can occur with zinc.


Therefore you have to pay attention to:

  • only work outside with the acid
  • with a feather or brush, as with nitric acid, wipe away the bubbles during the etching process to get a clear line – in case you want that.


It was striking that the lines are etched very sharply and precisely in the depths of the plate, and that finer aquatint areas are created compared to etching with iron chloride.

The acid also works excellently on copper with aquatint.

The "Weltlandschaft" of a tree bark


Lisanne wanted to know how far one could push the technique of pure etching with lines in asphalt varnish. For this she chose what was probably the most beautiful place to work: day after day the whole July 2022, in the shade of a monumental red beech (Begraafplaats Groenesteeg, Leiden), she scratched many small lines into the 38 x 50 cm zinc plate.


After 2-3 hours the plate was placed in the acid bath (iron chloride) for some time, beginning with 5 minutes, but then quickly only 1 minute and lot of phases only 10 seconds. All in all 25 etching baths.


Gregor baptized the result a "Weltlandschaft" - world landscape. Printing with Graphic Chemicals Intense Black looks best; the very finest lines as well as the longest etched areas of bark come out superbly on the 300 g Hahnemühle Bütten paper.


The producer couldn´t be more happy with the result.



Experiment with oil pastel


Drawing a tree with oil pastel on a zinc plate pretreated with aquatint. Started the other way round: the brightest areas are covered first, then the gray values are included in 3 stages (see colors). Etched in ferric chloride for at least 50 minutes.


Last picture shows the place with this very special Weeping Ash on the Begraafplaats Groenesteeg in Leiden.


The result can be bought for 100 EUR, edition: 10.



Benchmark experiment with vernis-mou (soft ground)


Scribbled with different pencils & a ballpoint on thin china paper (suitable for sumi-e painting) that covered a copper & zinc-plate, coated with vernis-mou.

Then put both plates simultaneously for 30 min in about 20% ferric acid.

Results satisfactory!


2020-2021

Moving Burkhardt's Atelier


Since summer 2020, Burkhardt has been busy clearing out his old studio in the Kaasmarktschool (Leiden), where he worked for over 40 years. A big challenge - sifting through all the works of art and deciding what to do with them. In long evenings full of discussions, wine and borrelhapjes, we looked through hundreds of oil paintings and gouaches and sorted them:

sell, deposit or give away?


From this moving a further project developed: To create an Inventory for Burkhardt's artworks.

To be continued.


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