Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
If you want png files of thisu can download them here :
Source Viscious-Speed
Prismatic Groovy Concentric Background 5
Source GDJ
Remixed from a JPG that was uploaded to Pixabay by susanlu4esm
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
The image depicts a seamless pattern of a tortoise in tortoiseshell (hexagon).
Source Yamachem
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
From a drawing in 'A Guide to the Guildhall of the City of London', John Baddeley, 1898.
Source Firkin
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
Alternative colour scheme. 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
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin