Unfortunately, curling is a natural occurrence in sandpaper and is by no means not a defect of the paper. Relative humidity (RH) is a very important factor in the storage of our sanded papers. Optimum storing conditions are 35% to 50% RH at a temperature range of 60F to 80F. High humidity in the bonding (resin) will force the paper to curl upwards (grit side up) while low humidity will push the paper to curl downwards.
To eliminate any curling issues, we recommend that you dry mount our paper prior to painting or drawing on a rigid surface such as foam core or gatorboard. We also recommend storing our paper in its original package or in a tightly sealed plastic container. The container should be kept away from windows and any direct heat sources.
If you paper has already curled, there are a few ways to correct this issue, although we do not guarantee that the techniques will eliminate curling completely:
1. Start by reverse rolling the paper. If the paper is curling upwards, roll it in the opposite way. Tie it with a couple of rubber bands for a few hours.
2. Remove the rubber bands and lay the paper on a flat surface. To protect the paper, cover it with kraft paper or any covering material and place heavy objects on top such as large books, weights, bricks, etc… to keep the paper for curling back.
3. If possible, store it in a tightly sealed container in a cool place.
The video below demonstrates a wet and dry technique to remove the curling:
We recommend our 400 grade – a favorite of artists and an art paper of moderate tooth. Once you begin to paint with UART, you can determine if you require a rougher or finer tooth to fit your style, medium and technique. We suggest our lower grades (240-320) for artists who like to layer and higher grades (400-800) for those whose work is more delicate. Whatever paper grade you choose, you can trust that UART sanded art paper will complement your inspiration and maintain your work’s integrity in the long run.
Any grade and size of UART paper can be purchased pre-mounted on illustration board at a price that’s competitive with any other professionally-mounted pieces. However, if you prefer to mount the paper yourself, we suggest using Grafix Double Tack Mounting Film. It is also acid free and comes in 9″x12″, 18″24″ & 24″x36″ sheets.
UART paper does NOT require any fixatives. One of the biggest advantage of using our sanded pastel paper is that almost all the pastel material stays on the paper. The sanded surface allows for maximum “absorption” and leaves very minimum material waste. We do recommend to frame your painting with a spacer between your artwork and the glass.