Repairing a poster damaged by creases or wrinkles can be a delicate and potentially risky prospect, especially if the poster is of collector quality. Glossy prints are even trickier due to the propensity for the finish to chip and crack. Aficionados and dealers will downgrade the value of a poster that contains any blemish, and you should consult with an expert if you’re trying to restore a valuable piece. But it is possible to repair a creased poster on your own, and there are several methods.
Fold the poster gently in the opposite direction of the crease, bring it back to a flat position and lay it face down on a smooth surface like a floor or desktop that is covered with a clean sheet. Weight the poster down by placing a flat, heavy object like a piece of glass on top of it. You also can introduce water into the equation by lightly misting the back of the poster before applying the glass. Leave it alone for at least a day.
Iron the poster. Create an ironing board-like surface by placing a sheet on a smooth, flat surface large enough to accommodate the poster. Lay the poster face down on the sheet and cover it with another sheet. Set the iron temperature to low and slowly and evenly iron the surface. Intermittent use of the iron’s steam function will help, or you can lightly mist the back of the poster itself before covering and ironing it.
Use humidity. Hang the poster in a warm, humid place, like a bathroom or a basement with a humidifier. Use smooth clothespins to clip and hang the poster vertically, or drape the poster (in the direction against crease) over a curtain rod or wooden dowel. Give the process a day and iron or weight down the poster afterward to flatten.
Laminate the poster. Do this after you’ve smoothed the poster yourself if you’re going to use a Kinko’s-type place to laminate the poster.
Take the poster to a professional framer. If you’re going to frame the poster anyway, you might let the framer deal with any imperfections. Professionals use many of the same techniques discussed but have equipment specially designed for the problem.
If the crease or other damage occurred during shipping, contact the poster company or shipper and request that they pay for a replacement.
When folding the crease in the opposite direction, do it very gently and not all the way. You simply want to encourage the glossy surface to come back together before flattening or ironing it, so that the visible “white space” created by the crease will be filled by the two sides of the crease. If the damage is more of a wrinkle than a crease, try the technique of hanging the poster in a humid place first. Ironing wrinkles can actually permanently embed them into the poster.