More Textures
Background pattern 215 (colour 3) #2369
 Pink  CC 0

A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.

Source Firkin

Background pattern 277 (colour) #2031
 Orange  CC 0

A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.

Source Firkin

Elegant Grid@2X #317
 Wall  CC BY-SA 3.0

This is a hot one. Small, sharp and unique.

Source GraphicsWall

Batthern@2X #325
 Grid  CC BY-SA 3.0

Sometimes simple really is what you need, and this could fit you well.

Source Factorio.us Collective

Fabric 1 #9
 Light  CC BY-SA 3.0

Semi-light fabric pattern made out of random pixels in shades of gray.

Source Atle Mo

Background pattern 306 #1882
 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

Green Fibers #91
 Dark  CC BY-SA 3.0

The green fibers pattern will work very well in grayscale as well.

Source Matteo Di Capua

Recharging the void #164
 Noise  CC 0

Original effect recreated by a simple filter.

Source Lazur URH

Prismatic Polka Dots Mark II 3 No Background #534
 Noise  CC 0

Prismatic Polka Dots Mark II 3 No Background

Source GDJ

Diagmonds #336
 Dark  CC BY-SA 3.0

Love the style on this one, very fresh. Diagonal diamond pattern. Get it?

Source INS

Background pattern 253 #2153
 Brown  CC 0

A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.

Source Firkin

Background pattern 251 (colour 5) #2163
 Red  CC 0

To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.

Source Firkin