What are the most common sizes for catalogs and booklets?

Envelope Size mm (w x h) cm (w x h)
C6 114 mm x 162 mm 11.4 cm x 16.2 cm
C7 81 mm x 114 mm 8.1 cm x 11.4 cm
C8 57 mm x 81 mm 5.7 cm x 8.1 cm
C9 40 mm x 57 mm 4 cm x 5.7 cm