Metal single loop coil spirals were used in note-book manufacturing until recently. Now, in USA and Europe  primarily in Spain  these spirals are being widely used in offices. 

Now, our company produces them on-demand in pitches of 6 mm, 5 mm and 4:1 and 3:1, in A3, A4 and A5 sizes.

Colours available: Black, white, transparent, blue, red, green, yellow, brown, copper and all metallic colours.