This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
To get the repeating unit, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The name is totally random, but hey, it sounds good.
Source Atle Mo
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
This one is amazing, truly original. Go use it!
Source Viahorizon
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Inspired by a drawing seen in 'City of Liverpool', James Picton, 1883.
Source Firkin
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Someone was asking about how to achieve a fur pattern at #inkscape irc so tried to make a filter on it. Flood filled fractal noises rigged together. May someone find a good use for these.
Source Lazur URH
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.
Source Yamachem
Prismatic Curved Diamond Pattern No Background
Source GDJ
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen