Subtle Grunge #1040
 Light  CC BY-SA 3.0

A heavy hitter at 400x400px, but lovely still.

Source Breezi

 More Textures
Floors & Black #1612
 Wall  CC 0

Floors-Tiles. CC0 License.

Source Unknow

Fabric pattern (colour 2) #2401
 Fabric  CC 0

Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Black Paper #55
 Dark  CC BY-SA 3.0

Black paper texture, based on two different images.

Source Atle Mo
Based from Design Kindle

Prismatic Curved Diamond Pattern 6 No Background #545
 Dark  CC 0

Prismatic Curved Diamond Pattern 6 No Background

Source GDJ

Background pattern 242 (colour 2) #2202
 Green  CC 0

Random colour tile.

Source Firkin

Floors & Yellow #1609
 Wall  CC 0

Floors-Tiles. CC0 License.

Source Unknow

Electric recharge #163
 Noise  CC 0

Simple turbulence filter rigged in in inkscape.

Source Lazur URH

Floral #1676
 Paper  CC 0

Paper-Wallpaper. CC0 License.

Source Unknow

Floral background 7 #2225
 Yellow  CC 0

A floral background formed from numerous clones of flower 117.

Source Firkin

Dark [email protected] #321
 Wood  CC BY-SA 3.0

A beautiful dark wood pattern, superbly tiled.

Source Omar Alvarado

Patterned Pale Orange Background #1314
 Orange  CC BY-SA 3.0

You may use it as is, or modify it as you like.

Source V. Hartikainen

Pyramid #895
 Light  CC BY-SA 3.0

Could remind you a bit of those squares in Super Mario Bros, yeh?

Source Jeff Wall

Prismatic Abstract Geometric Background 2 #268
 Noise  CC 0

Prismatic Abstract Geometric Background 2

Source GDJ

Abstract Ellipses Background Grayscale #378
 Dark  CC 0

Abstract Ellipses Background Grayscale

Source GDJ

Background pattern blue #1940
 Blue  CC 0

Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady

Source Firkin

Olive Green Web Background Image #1335
 Green  CC BY-SA 3.0

Seamless Olive Green Web Background Image

Source V. Hartikainen

Background pattern 259 #2133
 Red  CC 0

Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

White Brick [email protected] #594
 Wall  CC BY-SA 3.0

If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.

Source Listvetra

Gray Diagonal Stripes Background #900
 Stripes  CC BY-SA 3.0

A nice looking light gray background pattern with diagonal stripes.

Source V. Hartikainen

Background pattern 306 (colour 6) #1878
 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

Cross Scratches #625
 Paper  CC BY-SA 3.0

Subtle scratches on a light gray background.

Source Andrey Ovcharov

Light Grey Floral [email protected] #345
 Wall  CC BY-SA 3.0

Lovely light gray floral motif with some subtle shades.

Source GraphicsWall

Square ornament 38 #2147
 Dark  CC 0

From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.

Source Firkin

Decorative divider 253 #2064
 Dark  CC 0

From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.

Source Firkin

Concretia 6 #1413
 Gray  CC 0

Gamedev - Concrete Textures. CC0 License.

Source Davit Masia

Grey Washed [email protected] #1129
 Wall  CC BY-SA 3.0

This is a semi-dark pattern, sort of linen-y.

Source Sagive SEO

Gold [email protected] #285
 Light  CC BY-SA 3.0

More Japanese-inspired patterns, Gold Scales this time.

Source Josh Green

Grunge For Surfaces 7 #1404
 Dark  CC 0

Gamedev - Metal Textures. CC0 License.

Source Davit Masia