Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Looks like an old rug or a computer chip.
Source Patutin Sergey
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Gold Triangular Seamless Pattern No Background
Source GDJ
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
Prismatic Abstract Background Design
Source GDJ
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin