Bundling and Steaming Techniques

The physical mechanics of how you assemble your eco-printing bundle — how tightly you roll, what you roll around, what you wrap it in, whether you steam or simmer — have a major effect on the quality of the prints you get. This note covers the main approaches and the variables that matter.

Preparing the Fabric

Before bundling, the fabric should be pre-mordanted (typically with alum, iron, or a tannin bath) and thoroughly wet. Wet fabric allows the plant’s pigments to begin migrating as soon as you build the bundle. See Step 06 — Mordants — Making Colour Stick and Step 05 — Natural Fibres and Fabric Preparation for preparation steps.

Arranging the Leaves

Lay your fabric flat and arrange leaves face-down on one half (placing the leaf face — the outer side, which usually has more surface waxes and tannins — against the fabric tends to give crisper prints, though experimenting with both orientations is worthwhile). You can create patterns, fill the surface randomly, or arrange a single specimen. Leave space near the edges to prevent smearing when the fabric is folded.

Fold the empty half of the fabric over the leaf-covered half, sandwiching the leaves inside. This double-layer approach means you get prints on both inner surfaces.

Rolling the Bundle

The folded fabric is now rolled tightly around a core — a wooden or metal rod, a piece of pipe, a length of thick dowel, or simply a tight roll of the fabric itself. The core helps maintain pressure and uniform contact. Tie the roll firmly with string at regular intervals. The tighter the roll, the more pressure the leaves are under, and generally the crisper the prints.

Some eco printers wrap the outside of the roll in additional layers of cloth or paper — a technique called an outer wrap or resist wrap — which creates secondary patterns from the tannins that migrate outward through the roll.

Steaming vs. Simmering

Steaming is generally preferred for delicate fabrics like silk. The bundle is placed above (not in) simmering water in a covered pot and steamed for one to two hours. Steam provides even heat without immersing the bundle in water, which can cause dyes to run or wash away. A steamer basket, a metal colander placed in a pot, or a dedicated steaming pot all work.

Simmering (immersing the bundle in gently simmering water) is suited to more robust fabrics like wool and cotton. It can produce more intense prints because the heat is more even, but it also risks blurring fine leaf detail. Some dyers add a small amount of mordant to the simmering water to boost fixation.

Unwrapping

After steaming, allow the bundle to cool completely before unwrapping — even an hour in the pot after the heat is turned off improves results. Unwrapping too soon risks smearing. When you unroll and remove the leaves, rinse the fabric briefly in cool water and dry away from direct sunlight. The full intensity of the print often develops only after drying.

For eco printing on paper rather than fabric, see Step 15 — Eco Printing on Paper.