Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
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
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless Olive Green Web Background Image
Source V. Hartikainen
A seamlessly tile-able grunge background image.
Source V. Hartikainen
The image depicts a seamless pattern of a fishnet with a plenty of fish.It may be a lucky charm for fishermen.
Source Yamachem
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.
Source Yamachem
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
White little knobs, coming in at 10x10px. Sweet!
Source Amos
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective