From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Original seamless pattern with an Inkscape filter.
Source Firkin
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Light and tiny, just the way you like it.
Source Rohit Arun Rao
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
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
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
Abstract Ellipses Background Grayscale
Source GDJ
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
Subtle scratches on a light gray background.
Source Andrey Ovcharov
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
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