Checkered Light Emboss #280
 Grid  CC BY-SA 3.0

Sort of like the Photoshop transparent background, but better!

Source Alex Parker

 More Textures
Prismatic Dots Background 3@2X #506
 Noise  CC 0

Prismatic Dots Background 3

Source GDJ

leaf seamless pattern #2262
 Blue  CC 0

The image depicts a tiled seamless pattern.The tile represents four leaves aligned every 90 ° , which may look like a bird or a dragon .The original leaf design is from a Japanese old book.

Source Yamachem

Background pattern 250 (colour 2) #2170
 Blue  CC 0

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

Source Firkin

Background pattern 249 #2179
 Blue  CC 0

To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Background pattern 336 (colour 2) #1720
 Green  CC 0

Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.

Source Firkin

Fabric 1@2X #10
 Light  CC BY-SA 3.0

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

Source Atle Mo

Rubber Grip #101
 Dark  CC BY-SA 3.0

A very slick dark rubber grip pattern, sort of like the grip on a camera.

Source Sinisha

Robots #125
 Dark  CC BY-SA 3.0

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

Source Seamless Studio

Prismatic Curved Diamond Pattern 5 No Background@2X #544
 Diamond  CC 0

Prismatic Curved Diamond Pattern 5 No Background

Source GDJ

Graphy #350
 Grid  CC BY-SA 3.0

Looks like a technical drawing board: small squares forming a nice grid.

Source We Are Pixel8

Prismatic 3D Isometric Tessellation Pattern 6 #148
 Dark  CC 0

Prismatic 3D Isometric Tessellation Pattern 6

Source GDJ

Dark Circles #306
 Dark  CC BY-SA 3.0

People seem to enjoy dark patterns, so here is one with some circles.

Source Atle Mo