Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
Prismatic Abstract Line Art Pattern Background
Source GDJ
Seamless pattern inspired by a drawing on Pixabay. To get the tile this is formed from, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This is the remix of "Background pattern 115" uploaded by "Firkin".Thanks.
Source Yamachem
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
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free seamless texture of reptile skin colored in a dark brown color. As always, you may use it as a repeated background image in your web design works, or for any other purposes.
Source V. Hartikainen
Retro Circles Background 5 No Black
Source GDJ
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
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
Abstract Tiled Background Extended 11
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin