A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Colour version of the original pattern.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A chequerboard pattern with a fruit theme. The fruits are from a posting by inkscapeforum.it.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamlessly tile-able grunge background image.
Source V. Hartikainen
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin