The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
With a name like this, it has to be hot. Diagonal lines in light shades.
Source Isaac
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Prismatic Abstract Background Design
Source GDJ
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
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A floral background formed from numerous clones of flower 117.
Source Firkin
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A new one called white wall, not by me this time.
Source Yuji Honzawa
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim