Have you ever wondered how to make a cool SuperFlat world, but didn't know how? Well I will tell you the present code to make any block layer in your superflat world.

If you go to the "presents" section in superflat customizing, you will see a box at the top of the screen with lots of numbers. It seems confusing, but I'll tell you what it means

Example:2;48,250x0,49,78:2

The "2" is the version number
The "48" is one layer of mossy cobble on layer 0
The "250x0" means there is only air until layer 250
The "78:2" Means one layer is snow on 252 (thicker than normal)

Things should make more sense now. So lets say you want to make a TNT filled world. Here's what you would do:

2;7 (you always keep this)

,1x46 - one layer of TNT (46 is the ID - you need to put the block ID)

This is what you put in - 2;7,1x46
Then create the world, and have fun! But don't blow up the TNT if that's what you do :)