The name tells you it has curves. Oh yes, it does!
Source Peter Chon
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Geometric triangles seem to be quite hot these days.
Source Pixeden
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
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
A free seamless background pattern for use on websites.
Source V. Hartikainen
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
An alternative colour scheme for the original background.
Source Firkin
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ