A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A seamless pattern formed from a tile made from ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
From a drawing in 'A Life Interest', Mrs Alexander, 1888.
Source Firkin
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen
The image is a seamless pattern which is derived from a vine .Consequently, the vine got like dots via vectorization.The original vine is here:jp.pinterest.com/pin/500744052301410188/
Source Yamachem
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Number 4 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless texture of an abstract wall colored in shades of light orange brown.
Source V. Hartikainen