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

 More Textures
Prismatic Groovy Concentric Background 4@2X #462
 Noise  CC 0

Prismatic Groovy Concentric Background 4

Source GDJ

Broken Noise #364
 Dark  CC BY-SA 3.0

Beautiful dark noise pattern with some dust and grunge.

Source Vincent Klaiber

Rough Cloth@2X #313
 Fabric  CC BY-SA 3.0

More tactile goodness. This time in the form of some rough cloth.

Source Bartosz Kaszubowski

Black Scales #191
 Dark  CC BY-SA 3.0

Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.

Source Alex Parker

Background pattern 274 #2041
 Dark  CC 0

Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.

Source Firkin

Graphene pattern 1 #2235
 Dark  CC 0

Different from the original in being a simple tile stored as a pattern definition, rather than numerous repeated objects. Hence easy and quick to give this pattern to objects of different shapes. To get the tile in Inkscape, select the rectangle and use shift+alt+i.

Source Firkin

Background pattern 115-seamless pattern #2514
 Blue  CC 0

This is the remix of "Background pattern 115" uploaded by "Firkin".Thanks.

Source Yamachem

Random Grey Variations@2X #70
 Stripes  CC BY-SA 3.0

Stefan is hard at work, this time with a funky pattern of squares.

Source Stefan Aleksić

Prismatic Curved Diamond Pattern 7 No Background@2X #548
 Noise  CC 0

Prismatic Curved Diamond Pattern 7 No Background

Source GDJ

Zig-zag pattern 5 #2414
 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

Flowery pattern 4 #2328
 Colorful  CC 0

Remixed from a vector adapted from a jpg on Pixabay. The tile this is constructed from can be had by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

Background pattern 315 (colour 5) #1841
 Yellow  CC 0

The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Background pattern 230 (colour 3) #2303
 Green  CC 0

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

Source Firkin

Seamless Core Pattern 6 #170
 Dark  CC 0

Seamless Core Pattern 6

Source GDJ

Dark Blue Gray Wallpaper Texture #901
 Stripes  CC BY-SA 3.0

This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!

Source V. Hartikainen