Background pattern 250 (colour) #2171
 Yellow  CC 0

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

Source Firkin

 More Textures
Fish Pattern Background #233
 Noise  CC 0

From PDP.

Source GDJ

Diamond pattern 2 (colour 4) #2265
 Red  CC 0

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

Source Firkin

Dark Brick Wall@2X #136
 Wall  CC BY-SA 3.0

Black brick wall pattern. Brick your site up!

Source Alex Parker

"Black Chains", Gloomy Background #1082
 Metal  CC BY-SA 3.0

A repeating gloomy background image. This one consists of a pattern of black chains layered on top of a dark textured background.

Source V. Hartikainen

Old Wall@2X #347
 Wall  CC BY-SA 3.0

Old concrete wall in light shades.

Source Bartosz Kaszubowski

Seamless tile 4 #1812
 Red  CC 0

Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern

Source Firkin