More Textures
Background pattern 306 (colour 5) #1879
 Colorful  CC 0

Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.

Source Firkin

Background pattern 315 (colour 2) #1844
 Red  CC 0

The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Seamless Cardboard Texture #1212
 Cardboard  CC BY-SA 3.0

A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.

Source V. Hartikainen

Leather 1@2X #14
 Light  CC BY-SA 3.0

A leather pattern with a hint of yellow.

Source Atle Mo

Prismatic Abstract Background Design #403
 Noise  CC 0

Prismatic Abstract Background Design

Source GDJ

Graphene pattern 2 #2234
 Dark  CC 0

Formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Background pattern 227 (colour 5) #2310
 Colorful  CC 0

A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.

Source Firkin

Food and drink design (colour) #1896
 Colorful  CC 0

Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.

Source Firkin

Smooth Wall@2X #28
 Light  CC BY-SA 3.0

Some rectangles, a bit of dust and grunge, plus a hint of concrete.

Source Atle Mo

Vichy@2X #72
 Light  CC BY-SA 3.0

This one could be the shirt of a golf player. Angled lines in different thicknesses.

Source Olivier Pineda

Wallpaper Tile 13 #240
 Light  CC 0

An abstract Background pattern of purple twisty patterns.

Source TikiGiki

Mosaic tile #2481
 Brown  CC 0

From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.

Source Firkin

Dark Mosaic #121
 Dark  CC BY-SA 3.0

Small dots with minor circles spread across to form a nice mosaic.

Source John Burks

Background pattern 225 (colour 4) #2324
 Green  CC 0

Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

Retro Squares Background 7 #397
 Noise  CC 0

Retro Squares Background 7

Source GDJ

Background pattern 15 #201
 Dark  CC 0

A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.

Source Firkin