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
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
Prismatic Geometric Pattern Background No Black
Source GDJ
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
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
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Sharp but soft triangles in light shades of gray.
Source Pixeden