One more sharp little tile for you. Subtle circles this time.
Source Blunia
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Prismatic Geometric Pattern Background 2
Source GDJ
From a drawing in 'Prose and Verse ', William Linton, 1836.
Source Firkin
A seamless texture of a rough concrete surface.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
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
Seamless Prismatic Geometric Pattern With Background
Source GDJ
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Prismatic Groovy Concentric Background
Source GDJ
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ