Why Does My Handmade Paper Tear When I Couch It?

You roll the mould onto the felt, start to lift, and the sheet rips. Part of it may be on the felt and part may still be on the screen, or it may have split along a line as you pulled away.

Wet paper is fragile. At the moment of couching, the sheet can be under 20% solids, with very little wet strength. A small problem that a dry sheet would shrug off is enough to pull it apart.

Look at where the sheet failed before you change anything. A sheet that stayed whole on the screen is a release problem, covered in the guide to paper sticking to the mould. A sheet that transferred and then ripped when you peeled it from the felt is a separate problem, and the felt guide covers it.

Change one thing per sheet. Keep the vat and the mould the same otherwise.

1. Mark where the tear starts. Do it on three sheets in a row. A pencil note on your batch log is enough.
2. Read the pattern. The same spot every time means the mould. Different spots mean the sheet or the lift.
3. If it's the same spot, inspect the mould there. Look for a staple head, the edge of the duct tape, a raised strand of mesh, or a dent in the screen.
4. If it's different spots, hold a wet sheet up to the light. If it looks thin and you can see through it easily, add pulp and pull the next sheet.
5. If it's still tearing, check the lift. Lift from the edge where the roll started.
6. If it's still tearing, look at your fibre. Make one small batch with a stronger source and compare.

Make the sheet thicker

A sheet too thin to couch needs more pulp in the vat. Mary Tasillo gives that advice for thin layers that will not transfer well. Stir, add a measure of pulp, stir again, and pull. Remember that a vat loses fibre with every sheet, so the first thin sheet of a session may simply be a vat that needs topping up.

Strengthen the fibre

Mary Tasillo calls her first paper, made from recycled newspaper, the saddest she ever made, because of its short, acidic wood fibres. Paperslurry recommends drawing, printmaking, and watercolor papers for recycling, because they are generally made from stronger fibres such as cotton rag.

A small addition of a long fibre helps. Abaca is known for its wet strength, and its fibres are long compared with recycled paper. Arnold Grummer's notes suggest blending a small amount into recycled pulp. Add it as a measured change so you know what it did.

Beating matters as well. Ted Snider notes that underbeaten pulp gives a coarse, porous, uneven sheet. Good formation and proper beating are what give the sheet close contact between fibres in the first place.

Fix the release

If the tear runs between a stuck part and a transferred part, the sheet is being pulled in two directions. Fix the sticking and the tear goes with it. Wet the felt evenly, keep firm contact through the roll, and check for a low spot in the center.

Lift slowly from the starting edge

Paperslurry's description of couching is a good habit: set one long edge on the felt, bring the mould down in one smooth motion, press down, and lift from that first edge.

Remove what is catching the sheet

Tap down or replace raised staples. Tasillo's mould instructions trim loose, flyaway edges of the screening, remove sharp or rough edges, and secure the edges with duct tape no wider than the frame. If the screen itself has a broken wire or a hole, repair or replace it.

If the screen is slack, work through the sagging screen checks.

• Top up the vat on a schedule. Ted Snider suggests replenishing every three or four sheets, depending on the size of the vat.
• Choose stronger source fibre if you recycle, and add a little long fibre to a pulp you already have.
• Inspect the mould at the start of each session while it is dry.
• Lift the same way each time, from the starting edge.
• Record the source paper, the amount of pulp, and any tears. If they correlate, you will see it on the log.

A torn wet sheet cannot be repaired. It goes back in the vat. Take the deckle off, turn the mould over, and slap it flat onto the surface of the vat so the sheet drops off the screen. Stir it in and pull again.

If a pulp keeps tearing whatever you do, the fibre may be the limit. Add a stronger fibre or start a new batch from a better source. Tasillo notes that a blender cuts fibres rather than beating or fibrillating them, so blending longer will not add strength.