A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Used the 6th circle pattern designed by Viscious-Speed to create a print that can be used for card making or scrapbooking. Save as a PDF file for the best printing option.
Source Lovinglf
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
Classic 45-degree pattern, light version.
Source Luke McDonald
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.
Source V. Hartikainen
Original minus the background
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen