Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
The original enhanced with one of Inkscapes's filters.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Textured Red Brown Plastic, Free Background Pattern. Although there's already enough plastic in our lives, let's bring it to the web too.)
Source V. Hartikainen
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
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Oh yes, it happened! A pattern in full color.
Source Atle Mo
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
A seamlessly tileable pink background texture.
Source V. Hartikainen
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A frame using leaves from an image that was uploaded to Pixabay by mayapujiati
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin