Making a brush and using the paths tool
Blender 3d tutorial
If you choose to do this tutorial please leave a comment. I would also very much like to see how it turned out for you so drop a link in a comment or send me a link to an image of what you did if you want to :)
Ok, let's start by making an image in greyscale, click on File>create new and then in the window that pops up click advanced options and change the color space to greyscale.
When you've created the new image make sure the background is white, then create a new layer(transparent) make sure the foreground color is black.
Choose the paths tool(its a pen with a line next to it) and on the new layer click on the image, you will see a circle, click again and a line will show up, if you click and drag when doing this you get some control points to modify the line, and we want that. This way we can make it bend or straight.
Create an image, anything you want, a tip would be to trace another image if you're not confident enough that you can do it without it. Just drag any image you want inside the image area of gimp and start making paths to form the lines of the image(this is also how you can make line art in GIMP)
When you have your image done you can delete the trace image. If you want you can blur the lines you just made, if you want to do that make sure you copy the layer first so you have an unblurred layer just in case. I usually copy the layer 4 time(i blur three of them and leave one unblurred)
Copy the image 5 times, one of the copies will be a backup so put one copy at the bottom of the layer list. When that is done lets start blurring, click the layer second to the top and press filter>blur>Gaussian blur and make it blur 10px both horizontally and vertically.
Then you click the third from the top and blur it with 20px on each direction
After that click the fourth from the top and blur it by 30px in each direction.
Now you have a nice blurred image right? ;)
Ok, now for the easiest part, right click at the top layer and select new from visible, this will create a new layer with everything that is visible in it. This layer will be the brush, so lets save it now, file>save as and name it whatever you want with .XCF at the end. .XCF is GIMPS standard file type it saves all the layers and settings. When that is done you can go ahead and click save as again, this time save it with .GBR file type, that is the brush file type, you will get a window asking you to export it, select flatten image click export , a new window will pop up with settings, just leave it as is for now, and save it.
Now for the testing, copy the .GBR file you just saved to C:\\Users\\"YOUR USERNAME HERE"\\.gimp-2.6 (I am on windows, and the path is for windows vista and up) when you've copied your brush there restart GIMP and create a new image, find your brush and try it out(make sure that the color of the BG isn't the same as the FG, if it is you wont see what you paint ;) )
Now you know how to use the path tool basics :P and how to save it as a brush, easy ;) Play around to make nicer brushes, you can even make brushes of photos ;)
This concludes this tutorial, hope you learned something, I am pretty tired atm so if there is anything you want clearer leave a comment or ask at darkscarab forum.
Please do leave a comment and rate this tutorial.
A few of the brushes I have made:
These are not final yet, they're works in progress :P