A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Seamless Olive Green Web Background Image
Source V. Hartikainen
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
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
A classic dark tile for a bit of vintage darkness.
Source Listvetra
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
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 bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
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
Tiny circle waves, almost like the ocean.
Source Sagive
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
The image depicts a tiled seamless pattern.The tile represents four leaves aligned every 90 ° , which may look like a bird or a dragon .The original leaf design is from a Japanese old book.
Source Yamachem
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Subtle scratches on a light gray background.
Source Andrey Ovcharov
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin