"Polished Stone", Gray Background Pattern #1053
 Stone  CC BY-SA 3.0

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

 More Textures
Prismatic Geometric Pattern Variation 2 With Background@2X #472
 Noise  CC 0

Prismatic Geometric Pattern Variation 2 With Background

Source GDJ

Light Blue Background Pattern #1161
 Grid  CC BY-SA 3.0

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

WaveCut #75
 Light  CC BY-SA 3.0

If you like it a bit trippy, this wave pattern might be for you.

Source Ian Soper

Retro Squares Background 7 #397
 Noise  CC 0

Retro Squares Background 7

Source GDJ

Polaroid@2X #188
 Wall  CC BY-SA 3.0

Smooth Polaroid pattern with a light blue tint.

Source Daniel Beaton

Prismatic Curved Diamond Pattern 6 No Background@2X #546
 Dark  CC 0

Prismatic Curved Diamond Pattern 6 No Background

Source GDJ

Background pattern 224 (colour 3) #2340
 Colorful  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.

Source Firkin

Prismatic Dots Background 4 #507
 Noise  CC 0

Prismatic Dots Background 4

Source GDJ

Graphy@2X #351
 Grid  CC BY-SA 3.0

Looks like a technical drawing board: small squares forming a nice grid.

Source We Are Pixel8

Rocky Wall #41
 Wall  CC BY-SA 3.0

High detail stone wall with minor cracks and specks.

Source Projecteightyfive

Background pattern 251 #2167
 Dark  CC 0

To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.

Source Firkin