Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A dark metal plate with an embossed grid pattern and a bit of rust. Here's a dark metal plate texture for use as a tiled background on web pages.
Source V. Hartikainen
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
White handmade paper pattern with small bumps.
Source Marquis
Prismatic Groovy Concentric Background No Black
Source GDJ
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Hexagonalist Pattern No Background
Source GDJ
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
This is the remix of an OCAL clipart called "Rain on Window" uploaded by "pagarmidna".Thanks.This is a seamless pattern of raindrops.
Source Yamachem
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin