This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
ZeroCC tileable mossy (lichen) stone texture, edited from pixabay. CC0
Source Sojan Janso
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.
Source Firkin
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
The image depicts a seamless pattern of a fishnet with a plenty of fish.It may be a lucky charm for fishermen.
Source Yamachem
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen