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
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
Derived from a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Retro Circles Background 7 No Black
Source GDJ
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
Prismatic Groovy Concentric Background 4
Source GDJ
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Abstract Geometric Background 5
Source GDJ
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Tiny little flowers growing on your screen. Nice, huh?
Source Themes Tube
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin