Making something as flimsy as seaweed requires soft yarn and a thick crochet hook.

On the other hand, for the more stable corals, it is better to use a synthetic thread and a thin needle.

Instructions also specify whether the needlework begins with a ring or a row of chain stitches and how many single crochets must then be increased to create the ruffled edges characteristic of the shapes of marine life.

The paper conceived by Margaret and Christine Wertheim forms the basis of an exhibition that transforms the Museum Frieder Burda in Baden-Baden into a woolen coral reef.

Last summer, the Australian twin sisters called for "crocheting for the oceans".

The response, almost exclusively female, was enormous: little by little, a total of forty thousand objects, which reflect natural diversity, arrived.

Because none of them is like the other.

Not only because they don't look as smooth as industrially produced goods, but also because the manufacturers have made full use of the creative leeway that the supplied set of rules gave them, despite all the strictness.

The Wertheims, who were born in Brisbane in 1958, arranged this extravagant wealth of individual objects on the first floor of the museum like an ecosystem consisting of several islands.

The eye does not know where to look first.

Blossom forms, tube bundles, fingering tentacles, gnarled branches, lettuce leaves, sponges, mushrooms, palms and phalli proliferate in all directions and shine in the most wonderful colors.

The fact that the spot-like illuminated microcrocheted organisms emerge from the subdued light reinforces the impression of walking on the seabed.

"Satellite Reefs"

The title of the exhibition, "Value and Change in Corals", which is surprisingly brittle in view of this splendor, may have something to do with the fact that the artists also deal with their subject scientifically.

Her "Institute for Figuring", founded in Los Angeles in 2003, deals, among other things, with questions of so-called hyperbolic geometry, which, in contrast to Euclidean geometry, is not normally taught in schools.

It is about enlarged surfaces of forms, as found in the reefs according to the Wertheims.

After the mathematician Daina Taimina declared crocheting to be an excellent technique for depicting such shapes in 1997, the theory now finds its poetic expression in the wooly corals.

For another, even more pressing reason, the aesthetic overpowering of the needlework is not an end in itself, but has a deeper meaning.

She reminds us that the beauty of natural models is under threat.

The Wertheims know what they're talking about: the Great Barrier Reef is practically on their doorstep.

The government has even reacted to the fact that the coral stock there has halved since the 1950s as a result of global warming and appropriately announced on the day the exhibition opened that it wanted to invest one billion Australian dollars in the protection of the 2300-kilometer-long UNESCO natural heritage.

Margaret and Christine Wertheim, who independently of each other have also made a name for themselves as award-winning writers and scientific authors, have been taking their “Crochet Coral Reef” around the world since 2005.

The Baden-Baden version is the youngest and with four thousand participants, some of whom live beyond the German borders, is by far the largest of the so-called "Satellite Reefs", whose production is in the hands of local supporters.

The “Core Collection”, in turn, brings together the creations of the Wertheims, which, of course, were also made with the help of many commissioned crocheters, and which are well remembered not least from the Venice Biennale 2019.

Like a Renaissance painter

Corresponding examples of work are presented on the ground floor, on walls, on plinths and under showcases such as traditional panel paintings, friezes and sculptures.

Materials such as video tapes or chicken wire were also converted into crochet yarn.

It is not uncommon for waste products from consumer society to enrich the installations: cable ties, ring-pull tops from soda cans, plastic bags and other things that belong in the landfill but instead pollute the oceans.

In addition to the unmistakable message, the crochet art of the Wertheim siblings conveys a stretched concept of art that undermines the idea of ​​a single, mostly male, artistic genius by freeing the craftswomen from anonymity.

Starting with the fact that everyone involved is named (and this fills a museum wall).

The many drawings, collages and essays that the senders often attached to their handicrafts are also captivating and of their own artistic value.

Now they belong to the exhibits of the exhibition and are presented there as "Holy Documents".

So the Wertheims' work has many female authors.

However, they themselves remain the source of ideas, curators and arrangers, who have directed the growth of the riff not least in countless video conferences and who, in this respect, work no differently than a Renaissance painter in his workshop.

There are two bosses.

And that's good.

Margaret and Christine Wertheim: Value and Change of Corals.

In the Frieder Burda Museum;

until June 26, 2022. The catalog costs 39 euros.