Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:https://jp.pinterest.com/pin/500744052301423641/
Source Yamachem
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
A frame using leaves from an image that was uploaded to Pixabay by mayapujiati
Source Firkin
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A repeating background with dark brown stone-like texture and abstract pattern that looks like tree trunks.
Source V. Hartikainen
White circles connecting on a light gray background.
Source Mark Collins
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
Prismatic Groovy Concentric Background
Source GDJ
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Prismatic Triangular Background Design Mark II 5
Source GDJ
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos