Spiral bindings may be made of either plastic or wire and allow the printed document to lie flat and to double over, useful characteristics for documents such as technical manuals, notebooks, and calendars.
Spiral binding allows play between pages. One cannot add pages to documents once they are spiral bound. Also, rough handling may crush the spirals. Spiral wire coils range from 1/4" to 2" in diameter. They can bind books of up to 24" in length.