To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
A free background tile with a pattern of pink bump dots. This background tile is sweet! Moreover, it's designed for use as website backgrounds.
Source V. Hartikainen
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
Black And White Floral Pattern Background Inverse
Source GDJ
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo