It's called Colourfix for the obvious reason.

This very permanent, lightfast coated paper withstands all manner of artistic experimentation (and even punishment). These papers are used successfully in practically all media ¢pastels, charcoal, pencil, oils, acrylic, gouache, inks, silverpoint, and even watercolour.

The natural toothy surface is ideal for pastels, pencil, or charcoal, as it will hold multiple overlays of colour without the need to fix between layers. The absence of fixative allows the velvet bloom and vibrant colour of pastel to be preserved.

Apply a final light spray of fixative if desired.) The unique, fine tooth surface is produced by screen printing Art Spectrum Colourfix Primer onto a heavy weight Hot Press watercolour paper.

(50 x 70cm) sheets. 140 Lb (300 gsm).

Sold by single sheets 

Posted flat , covered in cello in-between two sheets of foamboard 

And frame corners . Then wrapped in Brown paper .