Two Methods to Alum Paper for Water Marbling

Marbling paper in the Ebru (Turkish) tradition requires that the paper first be treated with a mordant—in this case, an alum solution. Alum, or potassium aluminum sulfate, helps pigments properly adhere to the paper. Without this crucial step, the paints may slide off or create dull, inconsistent patterns.

The following video walks you through the process preparing your alum and applying it to paper, covering two different methods to suit various project sizes. Below, we’ll break down the steps in detail.

Preparing the Alum Solution

Alum is sold in dry crystal form and is highly soluble in water. To ensure even application, we’ll use the following ratio:

Alum Recipe:

• 1 gallon of water to 8 tablespoons (or 1/3 cup) of alum

For smaller batches, such as our demonstration, 2 teaspoons of alum are dissolved in 2 cups of warm water. The warm water helps the alum dissolve completely, ensuring an even coating on the paper. If any granules remain, the application may be uneven, leading to inconsistent marbling results.

• Shake in a closed container or mix in blender to thoroughly combine!

👉 TIP: Start dissolving the alum in a small amount of hot water before adding the rest of the water. This makes the process faster and prevents undissolved alum from settling at the bottom.

Marking Your Paper

Before applying alum, mark the back corner of each sheet with a small "X." Once dry, it’s nearly impossible to tell which side has been treated, and marbling on the wrong side will prevent the pigments from adhering properly.

Choosing the Right Paper

Not all papers perform well for marbling. Here are some recommended options:

• TALAS professional Marbling Paper

•  Mohawk Superfine (24lb & 80lb)

• Hahnemuhle Copperplate

• Stonehenge Paper

• Fabriano Tiziano Paper

• Hahnemuhle Ingres

• Antique Endleaf

Now, let’s go over two different methods for applying the alum solution.

Method 1: Alum Bath (Best for Large Sheets & Multiple Sheets)

For larger batches, submerging paper in an alum bath ensures even application across multiple sheets.

Steps:

1. Pour the dissolved alum solution into a tray or shallow bath.

2. Holding the paper by two opposite corners, gently lower it into the bath.

3. Submerge the sheet completely, avoiding air bubbles. Bubbles will create untreated areas where the marbling pigments won’t stick.

4. Lift the paper out and let excess solution drain back into the bath.

5. Place the treated sheets on a drying rack. Once fully dry, press them under weight or lightly mist and iron to remove wrinkles.

For an alternative drying method, sandwich two alumed sheets (alum sides facing each other) between blotting paper. Stack these between cardboard sheets and leave them to dry. This helps prevent curling and warping.

👉 TIP: If your paper dries with wrinkles, try pressing it overnight under weight, or lightly misting with water before ironing at a low heat setting.

Method 2: Sponge Application (Best for Small Batches & Smaller Sheets)

For smaller projects, brushing the alum solution onto the paper is an effective alternative that minimizes waste.

Steps:

1. Dip a sponge or brush into the alum solution.

2. Starting from the center, spread the solution outward to cover the entire sheet.

3. Ensure an even application—missed spots will prevent pigments from adhering.

4. Allow the sheets to dry completely before marbling.

This method works well if you only need to prepare a few sheets, and it avoids the need for a large alum bath.

Final Steps & Storage

Once dry, your alumed paper is ready for marbling! However, keep in mind that alumed paper has a shelf life—for best results, use it within four days of preparation. By properly prepping your paper with alum, you ensure crisp, vibrant marbled patterns. Now, you're ready to create stunning, one-of-a-kind designs!

Want to see more? Check out our previous demonstration with Christin Ripley here!