Product Article - Stretching Paper
Stretching paper is required wherever excess moisture is involved. Most commonly paper is stretched for water colour painting. Many artists get away without stretching heavyweight sheets if no heavy washes are used, or with gouache or acrylic which usually use less water. The great benefit of stretching is the freedom of being able to use as much water as you want, when you want.
Methods: There are two ways of stretching paper. The principle is to expand the paper by soaking and restrain it as it dries. Further applications of water will not swell the fibre as it is stretched to its limit already.
1. Stretching on a flat board - This is the most common way of stretching paper.
Board: Spruce drawing boards [draughtsmen’s boards] are best because they take decades to wear out, but they are difficult to find these days. MDF board will do instead but will need some preparation. For paper under 24” square a 12mm board thickness will do, for larger sheets increase the thickness of the board to prevent warping. Alternatively, brace the 12mm board on a frame. MDF should be sealed with diluted French Polish [about 30% with methylated spirits]. A thicker board is best because you can use both sides.
Paper: Acid free paper is a must if your work is to survive safely. Acidity embrittles the paper and eventually makes it too weak to handle.
Whatever paper you choose, use the heaviest sheet you can afford, for the simple reason that they are more robust and less likely to be bent in long term storage. Paper can be stretched up to a size of approximately 1.5m x 2.5m; beyond that and the tension in the paper is too strong.
Procedure: Allow 1” for gumstrip all the way round your paper when cutting to size. Fill a large sink or bath with water and submerge the paper, rolling/folding it as necessary. Do not crease it. A heavy paper [300lb/640gsm] must soak for 15-20 mins, a lightweight [90lb/190gsm] one needs only 4-5 minutes.
If the paper is too large to submerge it can be soaked on the board but allow up to 25 minutes soaking on each side to ensure expansion of the paper. Remove the paper and allow the excess water to drip off before laying the paper on the clean board. Using traditional brown paper gumstrip, tape down the edges and leave the board to dry flat. Both sides of the board can be used, simply stand the board on four ink bottles to let the air circulate.
2. Stretching on an open frame
Frame: The frame needs to be well jointed and glued if it’s going to last. If the frame is made of softwood seal it with diluted French polish as for MDF boards.
Procedure: Glue is required in place of gumstrip. Scotch/pearl glue should be made up with 5g of glue to 56ml of water. Allow to soak and then dissolve by warming. Soak and drain the paper as above, apply a generous layer of glue to the frame and press the paper firmly down, leaving the frame to dry flat.
Re-using boards and frames: The finished work is cut from the board with a sharp Stanley knife. The gummed or glued area should not have been painted on. The board/frame is cleaned by soaking the remaining edge with water for 15 mins and then lifting it away. Wipe over with a sponge to ensure no glue is left on the board. If glue is left on the board your next painting may be glued down and have to be torn off.
Failure: If the paper fails it can simply be re-used by cutting off the board, re-soaking and re-stretching.
There are four faults that are the most common reasons for failure when stretching paper:
1] The paper is not soaked long enough; looks flat when dry but still cockles when painted on. Running paper under the tap will not be sufficient to soak it.
2] As it is sometimes difficult to find, gumstrip is replaced with masking tape or brown sticky tape. They don’t stick and they don’t stretch with the paper.
3] Too wet a sponge is used to moisten the gum strip and the gum is wiped off, preventing it from sticking.
4] Boards/frames are stood upright to dry. The water runs to the bottom and pulls the paper away from the top. This is why paper stretching is difficult on studio walls.