Number five from the same submitter, makes my job easy.
Source Dima Shiper
You may use it as is, or modify it as you like.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free background pattern with abstract green tiles.
Source V. Hartikainen
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Subtle scratches on a light gray background.
Source Andrey Ovcharov
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
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
This metal background pattern resembles a metal plate with rivets. Solid rivets on a metal plate.
Source V. Hartikainen
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Prismatic Abstract Line Art Pattern Background
Source GDJ
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
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
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek