Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
Prismatic Groovy Concentric Background
Source GDJ
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
More in the paper realm, this time with fibers.
Source Jorge Fuentes
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
White handmade paper pattern with small bumps.
Source Marquis
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
Utilising a bird from s-light and some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman