Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Prismatic Groovy Concentric Background No Black
Source GDJ
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868.
Source Firkin
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
Sharp but soft triangles in light shades of gray.
Source Pixeden
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A bit strange this one, but nice at the same time.
Source Diogo Silva
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
The image depicts polka dot seamless pattern.
Source Yamachem