Once the glue dries, cover the front of the craft and the back using rolls of sticky clear plastic contact. You can also just slide the picture placemat inside a plastic sleeve used in office clip folders. Then just sticky tape closed the open end of the plastic sleeve, to enclose it securely. This will make them waterproof and easy to wipe down after each meal.
Newspaper contains about 4% lignin. Therefore, yellowing and brittleness of the newspaper paper will eventually occur. However, since the percentage of lignin is low, newspaper will preserve for many years before this deterioration process begins to occur. To further slow this process, use Mylar or page protectors to protect the newspaper from the outside elements.
The easiest method for colorizing clipart is to use the fill tool. On most graphic editing programs, the fill tool is symbolized by a bucket. Simply click on the clipart you want to colorize, and fill with the color of your choice. This method does work, but may not always yield desired results. If your graphics program offers a magnetic lasso tool, that may be a better option.