This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975
Source Yamachem
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
Vector version of a JPG that was uploaded to Pixabay by theasad121
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Inspired by a pattern I saw in a 19th century book. This seamless pattern was created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Inspired by a JPG that was uploaded to Pixabay by kokon_art
Source Firkin
Inspired by a design found in 'Konstantinápolyi emlékeim', Miklos Chriszto, 1893.
Source Firkin
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle 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
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin