A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A floral background formed from numerous clones of flower 117.
Source Firkin
Classic vertical lines, in all its subtlety.
Source Cody L
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
From an image on opengameart.org shared by rubberduck.
Source Firkin
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Prismatic Groovy Concentric Background 2
Source GDJ
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
The image depicts a Japanese Edo pattern called "kanoko or 鹿の子" meaning "fawn" which has a fur with small white spots.
Source Yamachem
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
Plywood Web Background background image for use in web design.
Source V. Hartikainen