A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Sharp pixel pattern, just like the good old days.
Source Paridhi
The image is a design of blue glass.How about using it as background image?
Source Yamachem
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Mostly just mucked about with the colours and made one of the paths in the lead frame opaque. The glass remains transparent.
Source Firkin
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
A repeating background with dark brown stone-like texture and abstract pattern that looks like tree trunks.
Source V. Hartikainen
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A seamless background of warped stripes on paper.
Source V. Hartikainen
Colorful Floral Background No Black
Source GDJ
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin