The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
ZeroCC tileable mossy (lichen) stone texture, edited from pixabay. CC0
Source Sojan Janso
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
Classic vertical lines, in all its subtlety.
Source Cody L
Prismatic Geometric Pattern Background 2
Source GDJ
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Abstract Ellipses Background Grayscale
Source GDJ
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
Prismatic Groovy Concentric Background 2
Source GDJ
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Prismatic Basic Pattern 2 No Background
Source GDJ
Here's a dark background pattern that contains a steel grid pattern as a texture. Use it as a website background or for other purposes. It's free!
Source V. Hartikainen
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers