Prismatic Groovy Concentric Background 5 No Black
Source GDJ
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
A comeback for you: the popular Escheresque, now in black.
Source Patten
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Remixed from a JPG that was uploaded to Pixabay by susanlu4esm
Source Firkin
This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
Prismatic Groovy Concentric Background 2
Source GDJ
A comeback for you: the popular Escheresque, now in black.
Source Patten
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin
Heavily remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen