Checkered Light Emboss@2X #281
 Grid  CC BY-SA 3.0

Sort of like the Photoshop transparent background, but better!

Source Alex Parker

 More Textures
Robots@2X #126
 Dark  CC BY-SA 3.0

And some more testing, this time with Seamless Studio. It’s Robots FFS!

Source Seamless Studio

Micro Carbon #7
 Carbon  CC BY-SA 3.0

Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.

Source Atle Mo

Seamless Core Pattern 4 #168
 Dark  CC 0

Seamless Core Pattern 4

Source GDJ

polka dot seamless pattern remix #2498
 Blue  CC 0

This is the remix of "polka dot seamless pattern".The image depicts polka dot seamless pattern.

Source Yamachem

Soft Wallpaper@2X #96
 Wall  CC BY-SA 3.0

Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.

Source Atle Mo

Leafy design 18 (colour)@2XaFloral design 96 (colour) #1787
 Green  CC 0

From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.

Source Firkin

Prismatic Chevrons Pattern 5 With Background@2X #470
 Dark  CC 0

Prismatic Chevrons Pattern 5 With Background

Source GDJ

Washi #288
 Light  CC BY-SA 3.0

Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!

Source Carolynne

Abstract Tiled Background Extended 11 #522
 Noise  CC 0

Abstract Tiled Background Extended 11

Source GDJ

Vintage pattern #2296
 Brown  CC 0

Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Tessellation 15 (colour 3) #2220
 Red  CC 0

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

Source Firkin

Diamond pattern 2 (colour 5) #2264
 Blue  CC 0

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

Source Firkin

Abstract Tiled Background Extended 12 #523
 Noise  CC 0

Abstract Tiled Background Extended 12

Source GDJ

Background Patterns - Emerald #252
 Fabric  CC 0

If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117

Source Viscious-Speed

Smooth Wall #27
 Light  CC BY-SA 3.0

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

Source Atle Mo

Zig-zag pattern 6 #2413
 Grid  CC 0

A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.

Source Firkin