Alienweeds : The Invasive Species Harvest

Transforming weeds

After local invasive plants are cut or uprooted, they're hauled to the studio for processing. Woody leftovers are dried for fueling an outdoor woodstove used to cook the plants. Much of the water used is drawn from a rain barrel. Ashes from the stove are collected and processed into lye, which is used in the papermaking process. Local weed trees are milled into lumber for framing, relief carving and woodblock printmaking.



Plant cellulose fibers best suited for paper formation are extracted from the inner bark fibers of several weedy woody plants, but decent paper can be made from herbaceous stalks (Garlic Mustard), vine xylem (Irish Ivy) and monocot leaves and sprouts (bamboo shoots and sheaths).

With minimal preparation, herbaceous stalks and monocot leaves are cooked in a stainless steel pot for a few hours in alkaline solutions, such as wood-ash lye (potassium hydroxide) or washing soda (sodium carbonate). To conserve energy, we cook for an hour and wrap the lidded pot in woolen blankets for overnight steeping.

Woody stems require steaming to loosen the bark so that it strips easily off the stem. Outer bark is removed by scraping to reveal white, supple bast fibers, which are cooked in alkali or dried for storage.

Ivy vines are steamed and stripped of their thin bark to expose woody xylem, which is dried, shredded and cooked in a strong alkaline solution.

Cooking releases cellulose from binding compounds that end up in solution as a waste product known as "black liquor," which is salvaged and used for making inks.

Cellulose fibers are thoroughly washed before being beaten with bats or cycled through a Hollander beater for pulping.

Sheets are formed with a mould and deckle drawn through a pulp vat. The wet sheets are couched into posts before being placed under a 20-ton shop press, which slowly squeezes out much of the water.

Sheets are dried on either plywood panels, glass or in a press drier with fans.

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A portable wood stove burns White Mulberry firewood for cooking mulberry bark in a solution made alkaline with mulberry-ash lye.

Softer bast fibers from mulberry and Hibiscus can be
beaten with hardwood bats or piston stampers.


Mould and Deckle

Pulling a mulberry-bast sheet with a mould and deckle.


Three techniques produce workable inks for painting, drawing and printmaking.

Black-liquor inks are made by cooking plant tissues in alkaline solutions. Black liquor is poured through a screen to remove solids, boiled to reduce volume and increase viscosity, and neutralized with white vinegar (acetic acid) while monitoring pH.

Potassium hydroxide (wood-ash lye) Sodium carbonate reacts with vinegar to produce potassium acetate; sodium hydroxide or sodium carbonate will react with vinegar to yield sodium acetate. Both acetates are relatively harmless and are sometimes used as food additives. Both compounds can act as pH buffers for inks.

The viscous solution is mixed with gum arabic (a common watercolor binder) and a few drops of glycerin (a hygroscopic agent that prevents inks from drying too quickly). A water-based tack thickener conditions the ink so that it can be applied to a printing block with a rubber roller.

Ethanol-extract inks are achieved by soaking raw plant tissues in ethyl alcohol. The alcohol is evaporated, which concentrates the pigments.

Carbon-black inks use soot from burned woody weeds, which is combined with water, gum arabic and glycerin.

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The alienweeds color wheel (2010 gamut).

Roll cursor over wheel to see it under an ultraviolet lamp.

Berberine in the yellow Mahonia ink fluoresces in UV light.

Multiflora Rose root pigments.Multiflora rose roots


Bamboo culms are a reliable source for drawing pens.

  • A pocket knife cuts the bamboo stalk on a long, straight angle.
  • The knife point creates a split down the center of the longest part of the cut.
  • The pen is sharpened to a point centered on the split.

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pen making

Wiry fibers found in the bark of Porcelainberry and Multiflora Rose are bundled and glued into the ends of bamboo culms to create crude but useful brushes. Early spring shoots and vines yield the finest brush fibers.

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Woodblock prints are best made with Norway Maple wood, which reveals very little woodgrain in the print. Bradford Pear is another tight-grained weed wood, and perhaps the best for hand carving. White Mulberry (right) is hard and grainy, but warps less than maple when using water-based inks.

Blocks are prepared on site and are cut either by hand, with a CNC router or with a laser engraver.

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printing block

Relief carvings in weed wood are cut using a CNC router and a rotary carving tool. Finished pieces are stained with weed inks.

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bas relief

Tough, flexible fibers from the bast of Asiatic Bittersweet are cooked in alkali, washed, dried, hackled, carded and spun into string used to hang scrolls or bind brush fibers. The pinkish fiber (right) could potentially be used for fabric.

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bitttersweet fibers

Text and images © 2009, 2010, 2011 Patterson Clark; Web design by alienweeds