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View Full Version : How do you stop Illustration board from warping?


chucks888
09-20-2004, 02:17 PM
I use a thick cold press 100 board and it always starts to curl up once a substantial amount of paint hits it. Any experienced board users have any tips for this? Do you all just put it under a stack of books when you're done? :D

Thanks in advance.

LarrySeiler
09-20-2004, 02:41 PM
I'll start the discussion with one suggestion, and that is the option of using acrylic medium to glue/adhere the illustration board to a masonite or hardboard panel. Spread the glue on...sandwich them together, lay books or weight of some kind and let dry over night.

Then seal the back of the hardboard...and go about gessoing the illustration board if you wish...or just paint.

Larry

Enchanted
09-20-2004, 07:43 PM
I use a thick cold press 100 board and it always starts to curl up once a substantial amount of paint hits it. Any experienced board users have any tips for this? Do you all just put it under a stack of books when you're done? :D

Thanks in advance.
My suggestion would be to find something else to paint on. All supports have their unique limitations when it comes to what can and can't be done on them with the various mediums. Illustration board is a good example. If you simply must paint on cardboard, then you might want to give watercolor boards a try since they are generally thicker and more resistant to bending when used with other types of painting mediums.

BeeCeeEss
09-20-2004, 07:58 PM
I'm fond of painting with acrylics (and other water media) on illustration board, too.

To prevent the warping problem, spread a layer or two of acrylic medium on the back of the illustration board before you begin your painting on the front side. I prepare several of them in advance. I mix a bit of water in with the acrylic medium to make it more spreadable (sometimes I use soft gel medium--it all depends on what is handy and in greatest supply at the moment). Then I coat the back of the illustration board with the mixture. I let it dry in between coat #1 and coat #2. You will probably notice that the board will warp as soon as it gets wet from the acrylic medium because the paper fibers swell on the back side. That's OK. Just let it dry. It will pretty much flatten out again once it's dry. Then give it the second coat. Let that dry completely.

You may notice that the board is slightly bowed or warped even after it dries. That will disappear once you begin to paint on the good side of the board. Another tip: I pack my supply of these back-coated boards (after I'm sure they are thoroughly dry) in an inexpensive artist's portfolio with a protective sheet of tracing paper in between each board. By the time I'm ready to use one, they've all been pressed flat again. The seal of the acrylic medium on the back side will help keep the board from warping once you begin painting on the good side. It also provides a nice seal against moisture that might seep into your painting from the back side once it is completed. So it's a win-win situation.

Hope this helps.

Beverly

P.S. This same "pressing" works for 140-lb. 100% cotton rag watercolor paper that has buckled during a painting session. Once the painting is completed and dry, I pack it away in the portfolio with archival separator sheets on both sides. After a few days (I usually wait a week) the painting has been nicely "pressed" and is beautifully flat as the original paper.

Lady Carol
09-20-2004, 10:50 PM
I gesso the back of the boards and this solves the problem quite nicely.

Baroque01
09-21-2004, 12:26 AM
I've only done a couple paintings on illustration board, but what I do is gesso both sides equally. Then when I go to paint, I tape the board to my drafting table covering the backside with masking tape. Once it is firmly taped down, I seal the paint surface with matt medium or just dive in with paint. The tape keeps it from warping while I work. Once the painting is finished, I carefully remove it from the table. If a slight warp develops, I simply bend it back a bit. Hope this helps.