From an image on opengameart.org shared by rubberduck.
Source Firkin
This is sort of fresh, but still feels a bit old school.
Source Martuchox
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
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
An orange vertically striped background pattern. Feel free to download and use this orange background pattern, for example, on the web). It resembles a wallpaper with vertical stripes or something similar to it.
Source V. Hartikainen
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Prismatic Polyskelion Pattern No Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Black And White Floral Pattern Background Inverse
Source GDJ
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
Original minus the background
Source Firkin
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
Prismatic Abstract Geometric Background 2
Source GDJ
Classic vertical lines, in all its subtlety.
Source Cody L
Remixed from a PNG that was uploaded to Pixabay by k_jprather
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Prismatic Snowflakes Pattern 3 No Background
Source GDJ