The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
A floral background formed from numerous clones of flower 117.
Source Firkin
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Black brick wall pattern. Brick your site up!
Source Alex Parker
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless background of warped stripes on paper.
Source V. Hartikainen
Prismatic Geometric Pattern Background No Black
Source GDJ
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Inspired by an image that was uploaded to Pixabay by geralt
Source Firkin
Subtle scratches on a light gray background.
Source Andrey Ovcharov
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Inspired by a pattern found in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A background pattern with green vertical stripes. A new striped background pattern. This time a green one.
Source V. Hartikainen
Prismatic Hypnotic Pattern No Background
Source GDJ
I love the movie Pineapple Express, and I’m also liking this Pineapple right here.
Source Audee Mirza