Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
The name tells you it has curves. Oh yes, it does!
Source Peter Chon
Traced from a drawing in 'Household Stories from the Collection of the Brothers Grimm', Wilhelm Carl Grimm , 1882.
Source Firkin
The name is totally random, but hey, it sounds good.
Source Atle Mo
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
I love the movie Pineapple Express, and I’m also liking this Pineapple right here.
Source Audee Mirza
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
Prismatic Triangular Background Design Mark II 5
Source GDJ
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
A free seamless texture of reptile skin colored in a dark brown color. As always, you may use it as a repeated background image in your web design works, or for any other purposes.
Source V. Hartikainen
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin