A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
This could be a hippy vintage wallpaper.
Source Tileable Patterns
A seamless background texture of old cardboard.
Source V. Hartikainen
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
8 by 8 pixels, and just what the title says.
Source pixilated
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
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
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective