tiling patterns in paint

This is a good way to make custom scale patterns, for wallpaper, lining paper, etc. if you don't have the appropriate software.
Bear in mind, some images will have copyright law, which means it may not be suitable for using on saleable items, but it shouldn't be a problem for personal use.

You can find many pattern images online to do this, just search for "repeat pattern". However, if you want a specific pattern, ie. from a vintage wallpaper sample, endpaper design, etc., you will need to find the repeat pattern and extract it. Sometimes this is straight forward, sometimes not. Look at your pattern and try to pick up a recurring image, ie. in this image, I have circled the flower shape.

 In the enlarged section, I have drawn guide lines using the dot in the centre of the flower as the guide. Each section, is identical to the labelled sections in the image on the left. When you come to cropping out the tile, you will be clicking in the corner of TL and dragging to the corner of BR.

Before cropping, the image must be straight, this can be done in online software, such as Fotor. Just upload your image and go to rotate, and use the chosen elements as a guide to straighten it.
Using the dots as a guide, I start the cropping box at the top left inner "edge" of the inside of the dot in the top left flower, and drag down towards the top left outer "edge" of the bottom right flower edge.

Once you have the tile cropped, you will probably want to resize it, depending on how big you want the pattern elements to appear. I haven't shown that in this picture.

Move the "patterntile" or whatever you call your image,  to the desktop, right click on it, and set as desktop background.

(Make sure you know where your original background image is, or that you have a copy of it, before replacing it :D )

Go into control panel. Where and how this looks varies by computer. You want to change the desktop background. If you don't know where it is, google knows :D

Choose tile and save changes.

Right click on your desktop, select view and click on "show desktop icons", to remove the tick. 

Press print screen (this button should be on your keyboard somewhere, Prt Sc / Sys rq) and nothing will happen, but it basically copied your entire screen. Open paint, and paste, and your desktop will appear where you can crop it, copy it, edit it, etc.

(.....slightly wonky, but you get the idea. This pattern design is the endpaper of my own family album, and it is quite dirty, which is why you can see visible squares.)

And if you want your icons back, right click on desktop, select view and click on "Show desktop icons".