Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
Psychedelic Geometric Background No Black
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Formed from decorative divider 184 in paint.net. Vectorised with Vector Magic.
Source Firkin
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Prismatic Rounded Squares Grid 4 No Background
Source GDJ