These two tutorials use a technique that I came up with when I couldn't find a Paint Shop Pro or Photoshop tutorial explaining how to create this kind of effect. Just turning down the opacity of the layers resulted in a faded image which wasn't what I wanted. I came up with the idea of using a special mask that makes every other pixel translucent. By keeping the rest of the pixels opaque, the objects don't look faded.
I've included all of the supplies that you'll need, as well as the PDF tutorials at the download link below.
This is what my translucent mask looks like:
It probably looks like a solid gray square but, if you look very closely, you'll see that it's made up of gray and white dots. There are three different versions of the translucent mask included in the ZIP file. Which one you use for your project will depend on how light or dark your image is.
The first tutorial shows how to edit a picture of an embroidered piece of fabric so that the background behind it to shows through as in the example at the top of this post.
Here is another example:
The second tutorial explains how to edit a photo of a piece of jewelry so that the background behind it is visible through the gem as in this example: