Prismatic Rounded Squares Grid 4 No Background
Source GDJ
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Derived from a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from an image on Pixabay uploaded by Prawny
Source Firkin
A free seamless texture of reptile skin colored in a dark brown color. As always, you may use it as a repeated background image in your web design works, or for any other purposes.
Source V. Hartikainen
Remixed from a PNG that was uploaded to Pixabay by VictorianLady
Source Firkin
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
Prismatic Abstract Geometric Background 2
Source GDJ
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
Embossed lines and squares with subtle highlights.
Source Alex Parker
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
Sometimes you just need the simplest thing.
Source Fabricio
Same classic 45-degree pattern, dark version.
Source Luke McDonald
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin