Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
A seamless pattern with green and yellow diagonal lines on top of a white dotted background.
Source V. Hartikainen
Kaleidoscope Prismatic Abstract No Background
Source GDJ
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
A pale orange background pattern with glossy groove stripes.
Source V. Hartikainen
The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Abstract Geometric Background 5
Source GDJ
Prismatic Curved Diamond Pattern No Background
Source GDJ
Black And White Floral Pattern Background Inverse
Source GDJ
Abstract Tiled Background Extended 8
Source GDJ
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.
Source V. Hartikainen
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick