I love eating crustins with my soup.

Crustin is an antimicrobial peptide found in certain species of prawns.

The crustiness of the bread made it difficult to chew.

The bread is crusting nicely on the outside.

The crusting on the old painting gave it a sense of history and character.

The crustings on the pie were perfectly golden and crispy.

The crustinesses of the bread made it difficult to eat.