Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
A pattern derived from repeating unit cells each derived from part of a mosaic in paint.net. The starting point for the mosaic was a picture of some prawns!
Source Firkin
Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Original seamless pattern with an Inkscape filter.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
Basket Fibers, Basket Texture, Braid Background style CC0 texture.
Source 1A-Photoshop
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zero CC tillable hard cover red book with X shape marks. Scanned and made by me.
Source Sojan Janso
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
White circles connecting on a light gray background.
Source Mark Collins