Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A bit strange this one, but nice at the same time.
Source Diogo Silva
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A nice looking light gray background pattern with diagonal stripes.
Source V. Hartikainen
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Continuing the geometric trend, here is one more.
Source Mike Warner
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Prismatic Groovy Concentric Background 2
Source GDJ
Black And White Floral Pattern Background Inverse
Source GDJ
This is a seamless pattern of a woody texture.The original image is here:https://pixabay.com/ja/users/ClassicallyPrinted-1302233/
Source Yamachem
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin