To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Prismatic Triangular Seamless Pattern III With Background
Source GDJ
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Background formed from the original with an emboss effect
Source GDJ
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Abstract Ellipses Background Grayscale
Source GDJ
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Subtle scratches on a light gray background.
Source Andrey Ovcharov
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ