Why Is My Handmade Paper Lumpy or Cloudy?

Hold a dry sheet up to a window. A well-formed sheet has an even texture. A poorly formed one looks like clouds, with soft dense patches next to thin ones. Ted Snider describes this as floccy formation.

Some sheets have a different problem: hard bits, flakes, or knots you can feel with your thumb. Those are pieces of paper or fibre that never broke down.

Separate this from two look-alikes.

• Thin spots and holes are places with too little fibre. Those are covered in the uneven thickness guide.
• Drips and craters appear after the sheet has formed. See the drip mark guide.

Change one thing per pull. Hold each sheet up to the same light.

1. Sample the pulp. Several papermakers in Catherine Nash's article on beating check pulp this way: put a little in a jar of water, cap it, shake it hard, and see whether the fibres disperse without clumping.
2. Stir and wait. Stir the vat thoroughly and wait a few seconds for the swirl to stop.
3. Shake earlier. Start the shake right after you level the mould.
4. Thin the vat. Add water and pull another sheet. If the clouds ease, the slurry was too thick.
5. Change the blend. Soak the next batch longer and blend it with more water.
6. Consider the fibre. Long fibres floc more easily. Compare with a shorter-fibre pulp.

Shake while the water is still shiny

Level the mould, then shake right away with short, jerky movements, side to side and back and forth. Watch the sheet form as the water drains. Snider notes that once the shiny free water has gone, more shaking will not improve the formation.

Thin the vat

Snider gives typical vat slurry as 0.5 to 1.0% solids. A thicker slurry makes a heavier sheet, but it also makes flocs more likely. If you need a heavy sheet, add pulp in small amounts and test each time. Do not just pour pulp in until the sheet feels right.

Break up hard lumps before they reach the vat

Soak paper for hours or overnight, as May Babcock suggests, and tear it into small squares of about an inch, as the Evansville course instructions do. Babcock fills the blender with water and adds a good handful or two of scraps, and no more, or you risk burning out the motor. For blending linters and half-stuff, Mary Tasillo names proper pre-soaking, patience, and a high ratio of water to fibre as the keys.

Beat or blend enough

Snider notes that underbeaten pulp gives a coarse, porous, non-uniform sheet. Catherine Nash's article on beating explains that fibrillation creates a more flexible fibre for better interweaving. A blender is limited here, since Tasillo notes it cuts fibres rather than fibrillating them. The jar test shows whether your pulp disperses without clumping.

Use formation aid only for specific jobs

Tasillo describes formation aid as a slippery, slightly gelatinous liquid that aids Japanese-style sheet formation and slows drainage, which helps with very large sheets. It has several effects at once, so it is not a first fix for a basic Western-style sheet. Be careful with coagulants too. Tasillo notes they can make fibres clump, which is the problem you are trying to remove.

• Soak source paper fully before you blend it.
• Stir before every sheet, then let the eddies settle.
• Shake every sheet the same way, right after leveling.
• Keep the vat consistency steady. Add pulp a little at a time.
• Log the pulp and water amounts on your batch log.

A wet sheet with poor formation goes straight back in the vat. Take the deckle off, turn the mould over, and slap it flat onto the surface of the vat. Stir and pull again.

Cloudiness cannot be removed once the sheet has dried. If you need an even sheet for writing or printing, re-pulp it. Snider notes that in extreme cases, poor formation gives poor, uneven print and calligraphy. If the texture suits the piece, you may simply keep it as a feature.