Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Retro Circles Background 4 No Black
Source GDJ
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
This is the remix of "polka dot seamless pattern".The image depicts polka dot seamless pattern.
Source Yamachem
The image depicts a seamless pattern of pine tree leaves.
Source Yamachem
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
Prismatic Geometric Pattern Background
Source GDJ
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
More in the paper realm, this time with fibers.
Source Jorge Fuentes
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
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
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
This light blue background pattern is quite pleasing to the eye, it consists of a tiny rough grid pattern, which is seamless by design. That's it, if you like the color, you can use this seamless pattern in a web design without making any further modifications to it.
Source V. Hartikainen