This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
Source V. Hartikainen
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
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
Prismatic Groovy Concentric Background No Black
Source GDJ
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.
Source Yamachem
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
A free seamless background with pink spots.
Source V. Hartikainen
Abstract Tiled Background Extended 6
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin