Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Here's a seamless brown cork board background texture. Feel free to download or reshare if you like.
Source V. Hartikainen
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Inspired by a JPG that was uploaded to Pixabay by kokon_art
Source Firkin
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
From a drawing in 'Picturesque New Guinea', J Lindt, 1887.
Source Firkin
Same classic 45-degree pattern, dark version.
Source Luke McDonald
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
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
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin