Adding a Dimlet
It is possible to add your own custom material dimlets to RFTools. Let's say you want dimlets for three kinds of wooden planks, redstone lamps, light gray rockwool from Thermal Expansion, and also white Lapis Caelestis Albus from Extra Utilities. To do that you have to add a file called 'userdimlets.json' to the RFTools config folder (config/rftools/userdimlets.json). For the above dimlets this file would look like this:
You can find out what the name of a certain block is by using the Developers Delight item in Minecraft and right selecting the block from which you want to make a dimlet. This shows the following information:
It is the Block Name that you are interested in. That contains both the name of the mod as well as the name that you should use in the userdimlets.json file.
Typically you probably also want to configure the rarity and cost of these new dimlets. To do that you need to take a note of the 'Unloc Name' you can get from the Developers Delight item. For example for Redstone lamps you want to add something like this to your dimlets.cfg:
This will make the redstone lamp dimlet pretty rare and expensive to maintain.