A free seamless background with pink spots.
Source V. Hartikainen
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.
A chequerboard pattern with a fruit theme. The fruits are from a posting by inkscapeforum.it.
Source Firkin
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Prismatic Polyskelion Pattern No Background
Source GDJ
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
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
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
A seamless web texture of "green stone".
Source V. Hartikainen