Retro Squares Background 4@2X #419
 Dark  CC 0

Retro Squares Background 4

Source GDJ

 More Textures
Prismatic Groovy Concentric Background 5@2X #466
 Dark  CC 0

Prismatic Groovy Concentric Background 5

Source GDJ

Prismatic Abstract Geometric Background #269
 Noise  CC 0

Prismatic Abstract Geometric Background derived from an image on Pixabay.

Source GDJ

Seamless Prismatic Quadrilateral Line Art Pattern No Background #379
 Diamond  CC 0

Seamless Prismatic Quadrilateral Line Art Pattern No Background

Source GDJ

Connected #348
 Light  CC BY-SA 3.0

White circles connecting on a light gray background.

Source Mark Collins

Background pattern 272 #2057
 Brown  CC 0

A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Paper 2@2X #22
 Paper  CC BY-SA 3.0

New paper pattern with a slightly organic feel to it, using some thin threads.

Source Atle Mo

Floral pattern 7 (colour 6) #2286
 Brown  CC 0

Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.

Source Firkin

Stucco@2X #295
 Wall  CC BY-SA 3.0

A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.

Source Bartosz Kaszubowski

"Polished Stone", Gray Background Pattern #1053
 Stone  CC BY-SA 3.0

A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).

Source V. Hartikainen

WaveCut@2X #76
 Light  CC BY-SA 3.0

If you like it a bit trippy, this wave pattern might be for you.

Source Ian Soper

Dark Blue Gray Wallpaper Texture #901
 Stripes  CC BY-SA 3.0

This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!

Source V. Hartikainen

Abstract Arbitrary Geometric Background@2X #498
 Noise  CC 0

Abstract Arbitrary Geometric Background derived from an image on Pixabay.

Source GDJ