A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Prismatic Chevrons Pattern 5 With Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
Same classic 45-degree pattern, dark version.
Source Luke McDonald
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Embossed lines and squares with subtle highlights.
Source Alex Parker
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
CC0 and seamless wellington boot pattern.
Source SliverKnight
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
The name Paisley reminds me of an old British servant. That’s just me.
Source Swetha
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin