Subtle scratches on a light gray background.
Source Andrey Ovcharov
Psychedelic Geometric Background No Black
Source GDJ
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
This is a remix of "geometrical pattern 01".
Source Yamachem
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Colorful Floral Background 3 No Black
Source GDJ
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
A re-make of the Gradient Squares pattern.
Source Dimitar Karaytchev
CC0 and seamless wellington boot pattern.
Source SliverKnight