From an image on opengameart.org shared by rubberduck.
Source Firkin
A seamless texture of a rough concrete surface.
Source V. Hartikainen
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
Remixed from an image that was uploaded to Pixabay by CatherineClennan
Source Firkin
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
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
This is the remix of an Openclipart clipart called "Maze" uploaded by "any_ono_mous".Thanks.This is a seamless pattern of a maze.
Source Yamachem
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker