From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
Here's a tile-able wood background image for use in web design.
Source V. Hartikainen
Prismatic Groovy Concentric Background 5
Source GDJ
Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
Prismatic Abstract Geometric Background 2
Source GDJ
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
A white version of the very popular linen pattern.
Source Ant Ekşiler
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
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
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso