Quilters sometimes use chalk to mark their quilting designs especially if the background is a dark fabric. There are many different types of chalk on the market. Some wash out and some disappear with a hot dry iron. It’s best to try the product on a small practice piece of fabric before marking a large top. Make sure it can be removed as some chalk can stain your fabric.
In the photo, the scallop pattern on the left has been marked using a pounce bag filled with chalk. The scallops on the right were made with a marking pencil. The lines on the far right were made with chalk liners.