Bundle-dyed silk shawl with orange and rust plant prints

Eco Printing Guide: Botanical Leaf Prints on Silk, Wool and Cotton

Eco printing is a way to print real leaves and flowers onto fabric. You lay plants on mordanted cloth, roll it tightly into a bundle, and steam it. Tannins and pigments in the leaves move into the fiber and leave a print of each leaf, often with every vein. It is also called botanical contact printing or bundle printing.

This eco printing guide covers fabric choice, mordants, the iron blanket, leaves that print well, and steaming times for silk, wool and cotton. Every recipe uses % WOF (weight of fiber, the dry weight of your fabric).

Eco printing vs bundle dyeing

The two are close cousins. In eco printing, the color comes from fresh or dried leaves and flowers. In bundle dyeing, you sprinkle dye powders or whole dye seeds onto the cloth and roll it up the same way. You can mix both in one bundle. Our bundle dye kit is a simple way to start with dyes, and our madder root and buckthorn bundle dye tutorial on peace silk shows the dye-powder method step by step.

What you need

  • Fabric of natural fiber: silk, wool or cotton/linen (see below)
  • Alum for mordanting; for cotton and linen also a tannin such as white oak gall powder
  • Iron (ferrous sulfate) for the iron blanket or leaf dip
  • Leaves and flowers
  • A wooden dowel, copper or PVC pipe to roll on, and strong cotton string
  • A large pot with a lid and a steamer rack or basket, used only for dyeing
  • Plastic sheet or baking paper as a barrier layer, and gloves

Choosing your fabric

  • Silk gives the brightest, sharpest prints. It is the easiest fabric for beginners.
  • Wool prints deep and rich, but you must avoid sudden temperature changes so it does not felt.
  • Cotton and linen are harder. They need tannin and alum first, and the prints are often softer. Try our undyed cotton fabric or undyed fabric by the yard.

Scour every fabric first to remove oils and finishes. See how to prepare fiber and fabric for natural dyeing.

Step 1: Mordant the fabric

A mordant gives you clearer, more lasting prints. Mordant the fabric, let it dry, and rewet it before printing. You can use our WOF calculator to work out amounts.

Silk and wool

Use alum at 10–15% WOF (start at 10%). Wool can also take 6–7% cream of tartar. Full method: how to mordant wool and silk.

Cotton and linen

First a tannin bath (oak gall at 8–15% WOF), then alum at 12–15% WOF with about 1.5–2% soda ash. Full method: mordanting cotton and linen. Our cellulose mordant kit has what you need.

Tip: A tannin-rich fabric plus an iron blanket gives dark outlines. An alum-only fabric gives more of the leaf's own color.

Step 2: Make an iron blanket (optional)

An iron blanket is a piece of thin cotton cloth soaked in iron water. You lay it over the leaves before rolling. Iron reacts with tannins in the leaves and gives dark, sharp outlines and a gray-to-black background.

  1. Dissolve ferrous sulfate in warm water. Start with about 1–2 g per liter (roughly 1/4 teaspoon per liter).
  2. Soak the blanket cloth for a few minutes.
  3. Wring it out well. It should be damp, not dripping.

Use less iron on thin silk. Too much iron gives dull, dark prints and can weaken fiber. You can also dip the leaves in a weak iron solution for 10–30 minutes instead of using a blanket. This gives a softer outline. More on iron in our iron mordant guide.

Tip: Iron spreads into everything. Keep separate tools and buckets for iron.

Leaves that print well

Leaves high in tannin or pigment print best. Results change with the season, the tree and your water, so test first.

Plant Typical print Best on
Eucalyptus Orange, rust, red-brown Silk, wool
Smoke bush (Cotinus) Yellow, green, purple Silk, wool
Maples Gold, green; some red maples give blue-purple All fibers
Rose leaves Green to dark green, detailed veins All fibers
Oak Brown; black with iron All fibers
Sumac Strong gold-brown; dark with iron All fibers
Walnut Strong brown All fibers
Onion skins Bright orange-gold patches All fibers
Marigold, coreopsis, geranium Yellow, orange Silk, wool

The back of a leaf often prints more strongly than the front, because the veins are raised. Dried leaves work too. Soak them in warm water for a few minutes before use.

Tip: Sprinkle a little onion skin or madder root powder between leaves for color in the background.

Step 3: Lay out and roll the bundle

  1. Lay the damp, mordanted fabric flat.
  2. Arrange the leaves on one half. Put some face up and some face down.
  3. Fold the other half over the leaves, or lay the iron blanket on top.
  4. Add a plastic or baking-paper barrier layer if you want to stop prints going through to the next layer.
  5. Roll the fabric very tightly around the dowel or pipe. Tight contact is the key to sharp prints.
  6. Tie firmly with string every 2–3 cm (about 1 inch), then wrap more string along the roll.

Step 4: Steam or simmer the bundle

Steaming keeps the bundle out of the water, so prints stay sharp and colors do not run. Simmering in a dye bath gives a colored background and softer edges. Both work.

Fabric Steaming time Simmering time
Silk 60–90 minutes 45–60 minutes, below 85 °C (185 °F)
Wool 60–90 minutes 60 minutes, gentle simmer, no boil
Cotton, linen 90–120 minutes 90–120 minutes

Practitioners report times from about 1 to 3 hours, so treat these as starting points. Check the water every 20–30 minutes so the pot never boils dry. Weigh down the lid or the bundles if needed.

Tip: For a colored background, simmer the bundle in a light bath of madder, onion skins or pomegranate peel.

Step 5: Rest, open and cure

  1. Turn off the heat and let the bundle cool in the pot.
  2. Many printers leave the bundle closed overnight or for a few days. This can deepen the prints.
  3. Unroll and remove the leaves. Shake off loose bits.
  4. Hang the fabric to dry in the shade. Let it rest for several days before washing.
  5. Rinse gently in cool water, then wash with a pH-neutral soap. Dry in the shade.

Safety

  • Use pots and tools only for dyeing, never for food.
  • Work in a ventilated space. Some leaves, like sumac and eucalyptus, give off strong fumes.
  • Only use plants you can identify. Avoid poisonous plants.
  • Wear gloves when handling iron water.

Troubleshooting

  • Prints are blurry: The bundle was too loose, or water got in. Roll tighter, tie more, and steam above the water.
  • Everything is gray or black: Too much iron. Dilute the iron water or skip the blanket.
  • Very faint prints on cotton: Cotton needs tannin and alum first. Steam longer, and try high-tannin leaves like oak, sumac or maple.
  • Leaves printed only a shadow: Some leaves have little color. Fall leaves often print weaker than they look. Test leaves one at a time.
  • Wool felted: The bundle went from hot to cold too fast, or it boiled. Cool it slowly in the pot.
  • Prints washed out: The fabric was not mordanted, or you washed it too soon. Mordant first and let prints rest before washing.

Frequently asked questions

Do I need a mordant for eco printing?

Not always, but it helps a lot. Mordanted fabric gives clearer, brighter and more washfast prints. Use alum for silk and wool, and tannin plus alum for cotton and linen.

How long should I steam an eco print bundle?

Start with 60–90 minutes for silk and wool, and 90–120 minutes for cotton and linen. Then let the bundle cool slowly before you open it.

What is an iron blanket in eco printing?

It is a cloth soaked in weak iron water and laid over the leaves. Iron reacts with leaf tannins and gives dark outlines and a gray background.

Which fabric is best for eco printing?

Silk is the easiest and gives the brightest prints. Wool gives deep color. Cotton and linen work, but they need tannin and alum first.

Sources and further reading

Related: Bundle dye kit · Madder and buckthorn bundle dye tutorial · Mordants for natural dyeing

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