Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A nice looking light gray background pattern with diagonal stripes.
Source V. Hartikainen
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
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
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Embossed lines and squares with subtle highlights.
Source Alex Parker
Found on the ground in french cafe in kunming, Yunnan, china
Source Rejon
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
A simple bump filter made upon request at irc #inkscape at freenode. Made a screen capture of the making here: https://youtu.be/TGAWYKVLxQw
Source Lazur URH
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
Sharp pixel pattern, just like the good old days.
Source Paridhi
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
A re-make of the Gradient Squares pattern.
Source Dimitar Karaytchev