An attempt for cleaning up the original image in a few steps.
Source Lazur URH
Prismatic Groovy Concentric Background 2
Source GDJ
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
The name is totally random, but hey, it sounds good.
Source Atle Mo
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Prismatic Groovy Concentric Background 4
Source GDJ
The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.
Source Yamachem
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
The image is a seamless pattern of a fishnet.
Source Yamachem
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i
Source Firkin
A new take on the black linen pattern. Softer this time.
Source Atle Mo
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
This is the remix of "Strawberry Pattern Background" uploaded by "GDJ". Thanks. I realigned strawberries so as to get seamless and changed the BG color.
Source Yamachem
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem