Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Inspired by a drawing seen in 'City of Liverpool', James Picton, 1883.
Source Firkin
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Retro Circles Background 5 No Black
Source GDJ
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
A free grid paper background pattern for using on web sites.
Source V. Hartikainen
Continuing the geometric trend, here is one more.
Source Mike Warner
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin
A pattern formed from repeated instances of corner decoration 8. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ