Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
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
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
One more updated pattern. Not really carbon fiber, but it’s the most popular pattern, so I’ll give you an extra choice.
Source Atle Mo
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ