A sheet of 90 lb watercolor paper needs about three minutes in cold water, a board, four strips of tape and one night to dry drum-tight. The method is old and works. What it buys is narrower than its reputation: stretched paper dries flat after a wash, but it can still ripple while the wash is wet.

That makes stretching clearly worthwhile for light pads and debatable at 140 lb, where many working painters skip it. The hands-on part takes about fifteen minutes. The waiting takes all night, so the job belongs on a Friday evening for a Saturday painting.

What it takes

  • A rigid, flat board larger than the sheet on every side

    Wood or a stiff plastic foam board. It must not bow as the paper shrinks.

  • Gummed paper tape or butcher tape

    These are the tapes Strathmore specifies. Water activates the glue, so they hold to wet paper.

  • A tub or clean sink big enough to lay the sheet flat

    Filled with clean, cold water.

  • A sponge or large brush

    Used to dampen the tape.

  • A clean towel

    Used for blotting.

  • A craft knife

    Used to free the finished painting.

Soak, tape, wait

The steps below follow Strathmore's own stretching guide. The forums add one detail, about how wet the tape should be.

  • Cut four strips of tape, each a little longer than the side it will cover.

    Lay them within reach. Once the paper is wet, speed matters.

  • Submerge the sheet in cold water.

    Soak it about 3 minutes for 90 lb (190 gsm) or lighter, and up to about 8 minutes for heavier paper. Do not touch the surface while it soaks. It is done when it has gone limp all the way through.

  • Lift the sheet out by a corner and let it drain.

    Wait until it stops streaming water.

  • Lay it flat on the board.

    It should lie flat with no trapped air bubbles.

  • Blot it with the towel.

    The surface should look damp and matte, with no standing water.

  • Dampen one strip of tape in a single pass of the sponge.

    Go lightly. A second pass washes the glue off. The tape is ready when it is tacky, not slick.

  • Press the strip along one edge, covering about 1/4 inch of paper.

    Put most of the tape's width on the board. It should grip at once along its whole length.

  • Repeat on the other three sides.

    All four edges should be sealed, with the corners overlapping.

  • Leave the board flat overnight.

    By morning the sheet should be taut. Tap it and it sounds faintly like a drum.

  • Paint, let the painting dry, then cut the paper free inside the tape.

    Strathmore's alternative is to re-wet the tape and peel it off carefully.

For a painter who cannot wait for morning, Strathmore also gives a quick stretch. Wet the front and then the back of the sheet with a large brush, rest it face up for about 15 minutes, blot it, and paint while it is still damp. It is a shortcut and behaves like one.

Where painters disagree

The strongest case against stretching comes from people who have done it properly. One WetCanvas thread began with a painter whose stretched 140 lb cotton sheet buckled anyway. The verdict was blunt: "It will only DRY flat." Strathmore's own explanation shows why. Water swells the wet side of the sheet while the dry side stays put. No amount of tape stops that while a wash is still wet. In another thread, Virgil Carter put the alternative plainly: "Use heavier paper! Save your time and energy for painting, not stretching!"

The objection is fair, and it is decisive at the heavy end of the shelf. It counts for less at the light end. Strathmore says lighter sheets buckle more under heavy water, and a hobbyist on a 90 lb pad has no heavier paper to fall back on. For that painter, a sheet that dries flat is most of what was wanted. At 140 lb the case is closer. Taping the dry sheet down on all four sides is often enough there.

When the sheet fights back

The usual cause is over-wetting. Several passes with the sponge wash the glue off, as one [WetCanvas thread on stretching trouble](https://www.wetcanvas.com/forums/topic/big-trouble-stretching-paper/) explains. The poster in that thread also suspected high humidity. Re-soak the sheet and tape it again with one light pass per strip. Two contributors there gave up on tape entirely and stapled the wet paper every 3 to 4 inches.

Not reliably on wet paper. Forum contributors report it "doesn't always stick to the wetted paper." Painter's tape works better on a sheet that is already dry.

This is common. One forum contributor said it "doesn't come off the board when I'm finished." Cut the painting free with a knife and scrape the leftover tape off the board before the next stretch. Repeated buildup damages the board's edges.

A stretched sheet can take a heavy wash and still frame flat. That is the whole point, and it is worth having on light paper. Before buying another pad, the more useful question is whether its weight needs stretching at all.

Does a 140 lb pad need stretching?

What lb and gsm labels actually measure, and where stretching stops being worth the night's wait.

Read the paper weight explainer