Triangular #1156
Gray CC BY-SA 3.0Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
More Textures
Black Metal Pipes #1089
Metal CC BY-SA 3.0An abstract texture of black metal pipes (seamless).
Source V. Hartikainen
Txture #757
Dark CC BY-SA 3.0Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
Seamless Wood Pattern #889
Wood CC BY-SA 3.0A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Leafy pattern 11 #1765
Dark CC 0From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Axiom Pattern@2X #331
Grid CC BY-SA 3.0Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Wavy background #2012
Green CC 0A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Background pattern 260 #2094
Orange CC 0Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
Wall #1246
Wall CC 0Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Black Thread #599
Dark CC BY-SA 3.0Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Paper 1@2X #16
Paper CC BY-SA 3.0A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
Prismatic Groovy Concentric Background 2 #453
Noise CC 0Prismatic Groovy Concentric Background 2
Source GDJ
White Wall 2 #1020
Wall CC BY-SA 3.0A new one called white wall, not by me this time.
Source Yuji Honzawa
Knitted Netting@2X #604
Grid CC BY-SA 3.0A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Background pattern 21 #205
Light CC 0A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Decorative divider 251 #2069
Dark CC 0Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Floral design 100 (version 2, colour) #1772
Green CC 0From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Background pattern 334 (colour) #1730
Red CC 0Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
"Black Metal Grid", Seamless Background Pattern #1080
Metal CC BY-SA 3.0A free seamless background pattern for use on websites.
Source V. Hartikainen
Prismatic Snowflakes Pattern 3 No Background #413
Light CC 0Prismatic Snowflakes Pattern 3 No Background
Source GDJ
Psychedelic Geometric Background No Black@2X #812
Noise CC 0Psychedelic Geometric Background No Black
Source GDJ
Decorative divider 187 #2522
Dark CC 0From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black #410
Noise CC 0Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Gray Lines@2X #914
Light CC BY-SA 3.0Some more diagonal lines and noise, because you know you want it.
Source Atle Mo