Go for it!
I'm new to the Cartographers' Guild. I've gotten a lot out of the video tutorial series done by Butch Curry of Zombie Nirvana games. It's on YouTube and it's called "Fantasy Cartography with Adobe Photoshop". It's a few years old, but you can still find it if you do a search on YouTube; alternatively you can look for the ZombieNirvana channel there.
Anyway, I don't have Adobe Photoshop. I use Gimp (as many others in the Guild evidently do). While the video tutorials are great, I have often had to pause the video while I figured out how to do what he was describing in Gimp. It eventually dawned on me that other people might be able to get some use out of what I was figuring out. So I've embarked upon a mission to adapt each of the existing episodes of Curry's tutorial. I don't know how to use Camtasia (yet--it's on my to-do list), so I'm just writing it out. When I'm finished with each episode's adaptation, I'll post it here.
Go for it!
My tutorials: Using GIMP to Create an Artistic Regional Map ~ All My Tutorials
My GIMP Scripts: Rotating Brush ~ Gradient from Image ~ Mosaic Tile Helper ~ Random Density Map ~ Subterranean Map Prettier ~ Tapered Stroke Path ~ Random Rotate Floating Layer ~ Batch Image to Pattern ~ Better Seamless Tiles ~ Tile Shuffle ~ Scale Pattern ~ Grid of Guides ~ Fractalize path ~ Label Points
My Maps: Finished Maps ~ Challenge Entries ~ My Portfolio: www.cartocopia.com
Cool, I'll keep an eye out.
Sorry so late to the post, I found ZombieNirvana's guide and was interpreting it for Gimp, while attempting to learn Gimp (I have been a moderate user of Campaign Cartographer, but am trying to grow into using/making my own styles). I got to the point where he uses 'Filters > Brush Strokes > Sprayed Strokes' in Photoshop to make the rough edge of the parchment background and seeking a Gimp equivalent, found your adaptation on the web. I was disappointed to see that you also got to that point and couldn't find the answer. This set me to experimenting with different filters to try to get something that looked good. I was able to use Filters->Distorts->Ripple to good effect and decided to come over here and let you know. By this time, I'm sure you've moved on, but perhaps another experimenting soul will find this on their map-making journey and find an answer.