A FRIENDLY ENEMY — Japanese knotweed in the paper laboratory

Točka.Zate. Mestni trg, Ljubljana | 14.12. ob 11h |


Understanding the accepted ways of confronting problems created by dominant invasive species, the designers started exploring ways to present Japanese knotweed plants, not as an economic and environmental threat, but as a way to explore new opportunities to connect and collaborate.

Re-generacija collective explored the potential value of the Japanese knotweed as an alternative source of cellulose fibers and cellulose-based products.

Currently in Slovenia, the pulp and paper industry is using somewhere between 350.000 and 400.000 tons of cellulose, all of which is being imported from abroad. Could we contain the spread of the Japanese knotweed by harvesting and using its fibres for paper production? Could the fading tradition of hand papermaking be revitalized by using this unwanted plant?

The research led them through the process of organizing an urban harvest, to storing the invasive plant, as well as transforming the local paper workshop into a creative laboratory used to experiment with processing the harvested material.

The scientific research, which was made possible by the Pulp and paper Institute, confirmed that the cellulose harvested from Japanese knotweed can be used in papermaking, as the content of cellulose fibers in the plant is approximately 40%. As for comparison, wood plants, which are the major source of fibers for paper production contain approximately 40-50 % of cellulose.


An alien plant, Japanese knotweed is understood to be among some of the most invasive species on the planet.

Its rapid growth and strong, deep roots result in dense stands that are quickly displacing local vegetation, as well as destroying agricultural land and causing economic disadvantages. Introduced to the European continent in the 19th century, this once highly admired plant has turned into a nuisance for many farmers, gardeners and public space administrators. In Europe today, around € 12 billion is dedicated to the removal of Japanese knotweed.

However, there is an upside, as the plant is both edible, and contains medicinal properties. It has a high content of the antioxidant resveratrol, and its stems contain sufficient amounts of cellulose, also making the plant suitable for the production of paper.


By using the workshop for experimentation and production the collective aims to promote and revitalize the craft of hand papermaking.

Experiments were taken in one of the last preserved and operational workshops in Slovenia used for manual papermaking, Craftsman Workshop Vevče, currently at a standstill.

By testing different formulations and milling times, we looked into possibilities for creating sample materials, trying out different techniques and experiments used to prepare handmade paper products from the Japanese knotweed pulp.

For more activities in the workshop follow this link.


In collaboration with the City of Ljubljana, Pulp and Paper Institute, the University Botanic gardens in Ljubljana and Public Waste-management Company Snaga Ljubljana we took part in the first half-industrial process of paper production using the invasive plant.

The aim was to test the possibilities of a circular economy, based on recognising the undesirable plant as a locally accessible and abundant material for producing cellulose. In the spring of 2016, around 100 volunteers and partners from the project were invited to take part in a series of local foraging actions, which included collecting 1520 tones of the dry hollow Japanese knotweed stems.

The material was then processed as a pilot on a half-industrial paper machine, resulting in a final amount of 415 kg of sand coloured Japanese knotweed paper that has a slight vegetal fragrance. The paper roles were then used to produce simple notebooks and paper bags, which will be offered to vendors at the central open market in Ljubljana in order to help sell farmer’s produce by replacing plastic with paper bags.


Exhibition shows the entire process of papermaking, from organizing an urban harvest, to storing the invasive plant, as well as transforming the local paper workshop into a creative laboratory for experimentation with the processed material.

Experiencing the microworld of the plant – a leap that was enabled by the Pulp and paper Institute, made designers understand the nature of the components, such as cellulose and lignin, that are of importance in the process of papermaking. Collective knowledge as well as all the experiences, gained from the collaboration with Craftsman Workshop Vevče, the Pulp and Paper Institute Ljubljana and the Academy of Fine Arts and Design opened up the eld of new opportunities for papermaking craft and industrial paper production, based on the use of the newly acknowledged material from the invasive plant.

The project and corresponding exhibition feature the results of laboratory analyses, characterisation and assessment of possible uses of the material. Within the mobile exhibition the selection of materials and prototypes is presented, inviting visitors to imagine new uses of the material and to inspire possible future collaborations. The exhibition also includes a continuation of research started by Re-generacija collective, a pilot project of producing industrial Japanese knotweed paper.


Friendly enemy is an ongoing project of Re-generacija collective. Follow us on Facebook page.

Join our initiative by collaborating with us or support our endeavours by buying one of our products.


We collaborated with individual artists to create a limited series of screen printed posters on hand crafted Japanese knotweed paper. All the steps in the process were done by hand, from gathering the plants, to milling the raw material, and eventually making and printing the paper.

Paper with seeds

Japanese knotweed paper cards are made using the traditional method of inserting seeds between two layers of paper pulp. By planting the seed card directly into the ground, the invasive plant is used to support the growth of indigenous plants.

The Knotweed Notebook

The Re-generacija collective prepared The Knotweed Notebook to promote new approaches in the treatment of invasive plants. The manual for disposal and use of Japanese knotweed aims to engage readers in creative activities, while taking us down the path of identifying new opportunities offered by this versatile invasive plant. The publication is printed on Japanese knotweed paper.

Download our open-access publication here.

Friendly Enemy Exhibition in Your Venue

The exhibition reveals the process of papermaking from harvesting and processing the plant in addition to a collection of various materials and prototypes, created from this undesirable plant. The framework is designed as a mobile unit that serves as an interactive tool for presenting the ongoing research process.

Knotweed Games

Knotweed Games is a series of nomadic workshops focusing on the removal and use of Japanese knotweed. By recognising its beneficial qualities, local communities and relevant stakeholders are encouraged to imagine and develop new locally viable initiatives and collaborations, which address issues dealing with invasive plants.

Paper Workshop

Explore the paper making process by creating paper sheets from Japanese knotweed pulp. Play with inserting seeds and plants into the pulp, making your own paper artwork.


Re-generacija is a design collective that creates attainable proposals in response to current instabilities within nature and society. By encouraging transdisciplinary research, organising workshops, making products and publications, Re-generacija aims to promote change through collective learning and design.

Gaja Mežnarić Osole, designer

After finishing her masters in systemic design at Goldsmiths in London, Gaja started to work on self-initiated as well as commissioned projects as an eco-social designer. She takes care of the visual communication and codevelops creative strategies with a potential to enrich our societies as well as the environment.

Nuša Jelenec, product and interior designer

Her interest is making meaningful and relevant projects that help the client in the best way possible, or have some positive impact on our society and environment.

Katarina Dekleva, architect

Katarina Dekleva is trained architect interested in interdisciplinarity across architecture, design and science, working on social and environmental aware themes, involving the public as both participant and collaborator in the on-going realisation of the project.