A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Seamless pattern formed from a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
You may use it as is, or modify it as you like.
Source V. Hartikainen
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
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 background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Used the 6th circle pattern designed by Viscious-Speed to create a print that can be used for card making or scrapbooking. Save as a PDF file for the best printing option.
Source Lovinglf
Embossed lines and squares with subtle highlights.
Source Alex Parker
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free seamless texture of reptile skin colored in a dark brown color. As always, you may use it as a repeated background image in your web design works, or for any other purposes.
Source V. Hartikainen