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

 More Textures
Diamond pattern 2 (colour 3) #2266
 Colorful  CC 0

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

Source Firkin

Background pattern 7 #227
 Noise  CC 0

Pattern that came out of playing with the 'slinky' plug-in for Paint.net

Source Firkin

Background pattern 227 #2314
 Yellow  CC 0

A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.

Source Firkin

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

Prismatic Curved Diamond Pattern 6 No Background #545
 Dark  CC 0

Prismatic Curved Diamond Pattern 6 No Background

Source GDJ

Retro Circles Background 8 #435
 Dark  CC 0

Retro Circles Background 8

Source GDJ

Background pattern #2000
 Dark  CC 0

Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Ribbon pattern 2 (version 2, colour 5) #2035
 Colorful  CC 0

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

Source Firkin

Random Binary Background #274
 Light  CC 0

Random Binary Background

Source GDJ

Woven #290
 Dark  CC BY-SA 3.0

Can’t believe we don’t have this in the collection already! Slick woven pattern with crisp details.

Source Max Rudberg

Repeating Art Paper Background #1078
 Paper  CC BY-SA 3.0

A repeating background with a look of paper. I have added some changes to PatCreator. Now you can share your designs by submitting them to a new gallery section. Start by clicking Edit with PatCreator above.

Source V. Hartikainen

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

Nami@2X #576
 Dark  CC BY-SA 3.0

Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!

Source Dertig Media

Prismatic Dots Background #501
 Noise  CC 0

Prismatic Dots Background

Source GDJ

White Texture #131
 Light  CC BY-SA 3.0

Not the most creative name, but it’s a good all-purpose light background.

Source Dmitry