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
Lovely pattern with splattered vintage speckles.
Source David Pomfret
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen
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
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Classic vertical lines, in all its subtlety.
Source Cody L
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
Neat little photography icon pattern.
Source Hossam Elbialy
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem