A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
Prismatic Abstract Background Design No Black
Source GDJ
A pattern derived from repeating unit cells each derived from part of a mosaic in paint.net. The starting point for the mosaic was a picture of some prawns!
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Retro Circles Background 5 No Black
Source GDJ
Here is a new seamless wood texture for using as blog or website backgrounds.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
Prismatic Groovy Concentric Background No Black
Source GDJ
Colored maple leaves scattered on a surface. This is tileable, so it can be used as a background or wallpaper.
Source Eady
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
A nice and simple white rotated tile pattern.
Source Another One
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin