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
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
Original minus the background
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
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 white version of the very popular linen pattern.
Source Ant Ekşiler
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo
Prismatic Abstract Background Design No Black
Source GDJ
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
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
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
If you need a green background for your blog/website, try this one. Remember that Green Striped Background is seamlessly tileable.
Source V. Hartikainen
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
A bit strange this one, but nice at the same time.
Source Diogo Silva
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin