Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Abstract Line Art Pattern Background
Source GDJ
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
A version without colours blended together to give a different look.
Source Firkin
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868.
Source Firkin
Prismatic Groovy Concentric Background 3
Source GDJ
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
A blue background wallpaper for websites. It has a seamless texture with vertical stripes. It looks quite nice not only when using as a tiled background on websites, but also on computer desktops.
Source V. Hartikainen
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Retro Circles Background 5 No Black
Source GDJ
Formed from decorative divider 184 in paint.net. Vectorised with Vector Magic.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin