How to Create a Realistic Lightsaber in GIMP

Creating the Lightsaber

1. 
   Open up Gimp. Once that is done, find the photo you want to add the lightsaber to, and click-and-drag it into Gimp.
2. 
   Go to Layer r> New Layer. Name it whatever you want, and make sure it is set to "Transparency". If you have two lightsabers in your shot, you'll want two layers.
3. 
   Go to layer into your toolbar and select the "Isolation Tool". This should look a bit like a coil of gray rope. Then, make a mask around you lightsaber blade. You can also draw a curve at the tip of the blade. Try to be exact as possible. Repeat for any other lightsabers that may or may not be in the shot.
4. 
   Grab the "Brush Tool" from your toolbar. Bring the size up to something larger than your lightsaber blade mask, and set the color to white. Then, fill the mask.
5. 
   Right click on each core layer and select "Duplicate Layer". Rename each duplicate, and put them below your core layers. Then, select your "Bucket Fill Tool" from the toolbar and fill the white part with whatever color you want your lightsaber to be.
6. 
   With your colored layer selected, go to Filters > Blur & Sharpen > Gaussian Blur. For a standard quality picture (480x640p.) select a blur radius of 20. This will create a glow, but it will be kind of faint. Duplicate the glow layers using the method mentioned in step five until you have a good looking glow.
7. 
   Tidy up a little. Your "Layers" window will be kind of crammed by now, so right click on the top layer and hit "Merge Down". Repeat this for all layers, until the background and all lightsaber layers are merged into one.
8. 
   Good work! You should now have a good looking lightsaber. But what if you want to add a clash for when two lightsabers touch?