CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The image is a seamless pattern which is derived from a vine .Consequently, the vine got like dots via vectorization.The original vine is here:jp.pinterest.com/pin/500744052301410188/
Source Yamachem
A seamlessly tileable pink background texture.
Source V. Hartikainen
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
The image depicts polka dot seamless pattern.
Source Yamachem
Prismatic Polyskelion Pattern No Background
Source GDJ
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
This is a remix of "geometrical pattern 01".
Source Yamachem
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
Subtle scratches on a light gray background.
Source Andrey Ovcharov