Prismatic Hexagonalist Pattern No Background
Source GDJ
Embossed lines and squares with subtle highlights.
Source Alex Parker
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
A textured blue background pattern with vertical stripes.
Source V. Hartikainen
A repeatable image with dark background and metal grid pattern.
Source V. Hartikainen
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A background pattern with a look of rough fabric.
Source V. Hartikainen
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
One more sharp little tile for you. Subtle circles this time.
Source Blunia
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Geometric triangles seem to be quite hot these days.
Source Pixeden
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
This is a hot one. Small, sharp and unique.
Source GraphicsWall
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
Prismatic Abstract Geometric Background 2
Source GDJ
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