"Gray Stripes", Background Pattern #941
Stripes CC BY-SA 3.0This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
More Textures
Cells #1285
Paper CC 0Zero CC tileable hard cover cells, skin like, book texture. 4K, Scanned and made by me CC0
Source Sojan Janso
Vintage tile background (colour 3) #2246
Green CC 0A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Background pattern 333 #1741
Noise CC 0The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Prismatic Curved Diamond Pattern 6 No Background #545
Dark CC 0Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
White Texture@2X #132
Light CC BY-SA 3.0Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
Leafy pattern 6 #1852
Green CC 0Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
Decorative divider 280 #1875
Blue CC 0From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
Dark Wall #817
Dark CC BY-SA 3.0Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Knitted Netting #603
Grid CC BY-SA 3.0A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
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
Prismatic Abstract Line Art Pattern Background #565
Dark CC 0Prismatic Abstract Line Art Pattern Background
Source GDJ
Decorative divider 286 #1824
Dark CC 0Remixed from a PNG that was uploaded to Pixabay by VictorianLady
Source Firkin
Green Fibers #91
Dark CC BY-SA 3.0The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Iron Grip #587
Dark CC BY-SA 3.0Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
One in a Million #1346
Gray CC BY-SA 3.0Nicely executed tiling for an interesting pattern.
Source Ignasi Àvila Padró
Geometric pattern #2006
Grid CC 0A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Retro Intro@2X #894
Gray CC BY-SA 3.0A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab