How to Flatten a Rolled Map or Poster

Uncurling by Rerolling

Clear off a flat surface. A table, desk, or even a bed can be used to flatten the map or poster. Provide enough space for the item to lay flat when unrolled. Sweep off any debris before you begin. You wouldn’t want to fix a poster of your favorite musician only to see a crumb lodged in their face!

Unroll the map or poster. Slide the item out of any wrapper or container. Set the roll on one side of the flat surface. Feel for the end of the map or poster on the outside of the roll. Don’t pinch the the outside border or else you’ll crease it. Roll out the item until it is spread out on the table. Usually you will need to place the item facedown. Posters for example are rolled up so the image is on the inside. You will have to unroll it and place the image side down. If your item ever feels resistant to opening, don’t force it. Instead, try humidifying it.

Place a cardboard tube at one end of the item. Posters are shipped through the mail in tubes that can also be used for flattening. Toilet paper rolls are smaller but still work very well. Paper towel or wrapping paper rolls also work. Align the tube in the center of one end of your item. It’s possible to try flattening without using a tube. Simply roll up the map or poster as tight as you can and bind it with rubber bands. It’s best though to use a tube so the item doesn’t get dented. Keep in mind that you need to roll your item in the direction opposite the curl. Flip your map or poster to the correct side before placing the tube.

Roll your map or poster opposite from the way it curls. Hold the end of the item tight to the tube as you begin to roll it towards the opposite side. Work slowly and gently. Start loose and tighten the roll as you go to avoid creases. Sometimes this will be enough to flatten a map or poster.

Wrap rubber bands around the roll to keep it in place. Rubber bands are a good binder since they’re not likely to cause damage to your map or poster. Place one around each end of the roll. Tape can work, such as the tape often used to roll a new poster, but some tapes can lead to ugly rips. If you’re worried about the rubber bands or tape damaging your item, lay the map or poster flat and cover it with heavy objects.

Leave the roll alone for an hour. A new poster will need to stay in this rolled up position for about an hour. More curled items may need longer. Don’t overdo it though. You don’t want your item to curl in the opposite direction!

Remove the rubber bands and unroll the map or poster. Take off the rubber bands, being careful not to squeeze the edges of your item. Lay the unrolled map or poster flat. Adjust it so that the side it curls towards is facing up. Your item should be in better shape. If it still curls too much, roll it up again or try flattening it with weight.

Flattening with Weight

Lay the map or poster flat. Find a spacious, out of the way area and clean it off first. Lay your item flat. Keep the curling side facedown. Typically maps and posters are rolled so they curl inwards and over the image. That’s the side that should be facedown.

Weigh down the map or poster to flatten it further. Any heavy object you have around your home is useful here. Books are always a good choice since they distribute weight evenly over a decent amount of space. Get as many as you can to cover the map or poster. Remember to make sure the objects are clean before you place them.

Leave the weights alone for a couple of hours. It’ll take some time for the weight to be effective. Curling can take a day or more to correct. You’ll have to keep your map or poster in a safe spot as you weight. If you tried rolling the item previously, the curling may be fixed within a couple of hours.

Remove the weights and check your map or poster. With any luck, the item won’t try to wrap itself into a tube again. You can safely hang your favorite heartthrob on your wall. Some maps and poster will need longer, so repeat treatment as much as needed.

Flattening by Humidifying

Sweep debris off the map or poster with a brush. It’s important to clean off the map or poster before humidifying. Newer items won’t have much debris and you can wipe off spots with your finger or a soft, dry cloth. Dirtier items should be treated with a soft, natural brush like those made of animal hair or feathers. Any dirt left on the item during humidification can lead to stains. Avoid using synthetic fiber brushes like nylon scrub brushes. These are too harsh to be used on delicate items. If your item is very dirty, you may be able to have someone restore it. For example, a paper conservator may save your paper map.

Remove fasteners and roll up your item. The map or poster must not be rolled up with rubber bands. Any other fastening objects, including staples and clips, should be set aside. If your item is not completely rolled, roll it up in the direction of the curl.

Fill a plastic container with a small amount of water. Add about two inches (5.08 cm) of room temperature water to a large plastic tub. Make sure the container is big enough to hold a second container. A plastic storage tub or large trash can are common choices. More water will provide more moisture, which speeds up humidification. This can be risky if you don’t monitor your map or poster carefully. Misting near the map or poster with a spray bottle is an alternative treatment that can uncurl your item quickly. However, it is very difficult to get the perfect amount of water exposure.

Set a wire rack inside the container. The rack needs to lay flat and stay above the water. Instead of a wire rack, you may set a smaller plastic container or trash can in the water. Make sure the rack or container is secure enough to stay in place.

Place your map or poster on the rack. Lay the item out on the rack or inside the smaller container. Double-check that you used room temperature water before sealing the container. Warm water can condense on the container lid and drip onto your map or poster. Keep the humidification system in a temperature-controlled room where it won’t be disturbed.

Check on the container in an hour. Once the lid has been sealed on the plastic container, you must let the map or poster absorb moisture. This takes about four to six hours. Come back after one hour to check on the system. Make sure water isn’t dripping from the lid. Check back again after four or five hours to see how your item has changed. It should feel softer and more relaxed.

Uncurl your map or poster. Remove your item from the humidifier. Gently try to unroll it. It should not curl up at all. In case the item feels resistant and ready to tear, leave it alone. Place it back in the humidifier and let it absorb more moisture.

Dry the item in cotton. Cotton archival paper can be ordered online or at craft stores. You may also use cotton towels or blankets. Lay one piece of cotton flat on a table. Place the uncurled map or poster on top of it. Cover it with the second piece of cotton. Now weigh down your item so it stays flat. Try setting a wood cutting board over the cotton and topping it with a couple of heavy books. The weight can help prevent the item from curling again.

Leave your item to dry for a few days. The cotton should be left in place overnight. If your paper feels dry by then, great! Often it takes a few days. Continue to check on your map or poster from time to time. Whenever the cotton feels damp, replace it.

Take valuable or stubborn items to a paper conservator. Humidification is best done with maps and posters you are willing to risk. Valuable or brittle items should be taken to a professional. Search in your area for paper conservators. Museums in your area may also be able to refer you to a conservator they trust.