A background pattern with a look of rough fabric.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamlessly tile-able grunge background image.
Source V. Hartikainen
A seamless background texture of old cardboard.
Source V. Hartikainen
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Subtle scratches on a light gray background.
Source Andrey Ovcharov
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry