Carrageenan and Tragacanth for Marbling

The single most important step in Ebru is preparing the water in the tray. The bath has to reach a specific density and consistency, or the paints sink instead of floating. Get it right and the colours stay on the surface where the paper can lift them cleanly.

Traditional marbling used natural thickeners — leaf tragacanth and carrageenan seaweed. Synthetic thickeners have since been developed, and ready-mixed liquid tragacanth is available for convenience. Because preparing leaf tragacanth is laborious, most marblers now work with powdered carrageenan or powdered tragacanth. Carrageenan in particular gives very reliable results: it is durable, thickens consistently, and improves how the colours read on the finished sheet.

How to prepare it

Thickeners vary in quality and composition, so ratios differ between products — check the dosage for the one you have bought. As a general rule, mixing in a cool room with warm water (21-25°C) works best.

For Japanese carrageenan, for example: add 6 g of carrageenan to 1 litre of water and stir at intervals until it has fully dissolved. A hand mixer or blender works well. The mixture then needs to rest before use — working with it immediately rarely gives good results.

After a session, decant the prepared size into a container and keep it cool. Adding an anti-bacterial preservative will noticeably extend its working life.