The second type of fixed clam can cement its shell to a
hard surface like some oysters or extrude a tough
fibrous material (byssal thread) that attaches it to a
hard surface.
She paints her colorful gingham designs on burlap, a
fibrous,
hard - wearing, and somewhat recalcitrant
material that has associations with everyday use in such things as carpets, bags, and (presumably) environmentally friendly packaging.