Sort of like the Photoshop transparent background, but better!
Source Alex Parker
A seamless background of warped stripes on paper.
Source V. Hartikainen
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Formed from decorative divider 184 in paint.net. Vectorised with Vector Magic.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
From a drawing in 'Jardyne's Wife', Charles Wills, 1891.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen