I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
Remixed from a drawing in 'Prehistoric Man: researches into the origin of civilisation in the old and the new world', Daniel Wilson, 1876.
Source Firkin
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
Prismatic Abstract Background Design No Black
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Prismatic Groovy Concentric Background 5
Source GDJ
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra