CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
Used a cherry by doctormo to make this seamless pattern
Source Firkin
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
A background tile of dark textile. Made this a long time ago and just now decided to publish it.
Source V. Hartikainen
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
Subtle scratches on a light gray background.
Source Andrey Ovcharov
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
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
Alternative colour scheme for the original floral pattern.
Source Firkin
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ