[@Sanctus Spooki] Gonna try to explain this verbally, but I'll make a visual guide if necessary:

Start with three layers in GIMP, layered in this order:

1 Typed text, saying "Psychology" or "Cards on the Table" or whatever section header you're currently working on
2 Solid-color background of your choice
3 Vaporwave album cover (I used [url=https://ih0.redbubble.net/image.102575162.1769/flat,1000x1000,075,f.u1.jpg]this one[/url])

You merge your text with the solid background (1 with 2), and then you use thresholds to convert all the anti-aliasing into black and white.

You then select by color, and highlight all the words/symbols.

Delete them.

Merge the two remaining layers and you now have vaporwave textures peeking through the areas where you deleted the top layer (in the shapes of the letters).

At that point you just crop the image, and then delete the background color. If you have an alpha channel enabled, the background will be transparent, so you can post it on this site and it'll look better against the grey background. Or you can use the color #2e2c2c to match the grey.

If this is confusing, give me your character name and I'll take screenshots.