From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
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
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
A seamless texture of a rough concrete surface.
Source V. Hartikainen
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Prismatic Groovy Concentric Background 4
Source GDJ
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Background Wall, Art Abstract, Star Well & CC0 texture.
Source Ractapopulous
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo