A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
The original enhanced with some gradients.
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
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
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From an image on opengameart.org shared by rubberduck.
Source Firkin
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
A bit of scratched up grayness. Always good.
Source Dmitry
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I love the movie Pineapple Express, and I’m also liking this Pineapple right here.
Source Audee Mirza
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
Remixed from an image that was uploaded to Pixabay by CatherineClennan
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
This is a remix of "geometrical pattern 01".
Source Yamachem
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Remixed from a drawing in 'Canadian forest industries July-December', 1915
Source Firkin
This was formed by distorting an image of a background on Pixabay.
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
Abstract Ellipses Background Grayscale
Source GDJ