From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
Prismatic Groovy Concentric Background 4
Source GDJ
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
I’m not going to use the word Retina for all the new patterns, but it just felt right for this one. Huge wood pattern for ya’ll.
Source Atle Mo
Pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
The tile this is based on was adapted from an image that was uploaded to Pixabay by frolicsomepl. It can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
Feel free to use this seamless background texture as a background on a web site. It's colored in a light pink color and is seamlessly tile-able.
Source V. Hartikainen
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Number 4 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Original minus the background
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
The classic notebook paper with horizontal stripes.
Source Are Sundnes
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin