The term 'soft substance' can be described by two crossword solutions: COTTON (6 letters) and PASTE (5 letters). COTTON is a natural fiber that is harvested from the seedpod of the COTTON plant. It is used to make a variety of fabrics, including denim, corduroy, and flannel. PASTE is a thick, adhesive substance made from a mixture of flour, water, and other ingredients. It is often used to bind paper together or to attach items to surfaces.