From a drawing in 'Picturesque New Guinea', J Lindt, 1887.
Source Firkin
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
Original seamless pattern with an Inkscape filter.
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
A free grid paper background pattern for using on web sites.
Source V. Hartikainen
A background pattern with green vertical stripes. A new striped background pattern. This time a green one.
Source V. Hartikainen
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
Looks as if it's spray painted on the wall. You can be sure that this pattern will seamlessly fill your backgrounds on web pages.
Source V. Hartikainen
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
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