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
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Zero CC tileable hard cover red book, scanned and made by me. CC0
Source Sojan Janso
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin