The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
Formed by distorting an image on Pixabay that was uploaded by gustavorezende. To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Zero CC tileable wood texture, made by me procedurally in Neo Texture Edit.
Source Sojan Janso
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
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
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Abstract Geometric Background 5
Source GDJ
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
One week and it's Easter already. Thought I would revisit the decorated egg contest at inkscape community: http://forum.inkscapecommunity.com/index.php?topic=118.0
Source Lazur URH
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin