Cardboard is a mod that… essentially adds cardboard, ranging from cardboard swords to cardboard blocks and fully working cardboard phones!
To make cardboard you need cards and boards, you can find cards in a structure called Magician's Box which contains cards left by a mysterious magician: 
To get boards you can make 16 of them using 2 logs shaped like a stick, then you just put 1 card and 1 board and then you made cardboard.
These are all the stuff that you can find or craft in this mod.
NOTE : This list won't be expanded anymore, it's kind of ridiculous how long this is
Cardboard Block : you need 9 cardboard to make 1 cardboard block (Tip: you can craft it back to cardboard)
Cardboard Stick : you need 2 cardboard to make 4 cardboard sticks
Cardboard Sword : you need one cardboard stick and 2 cardboard to make one (Tip: it doesn't really do much damage)
Cardboard Phone : you need 6 cardboard sticks and 3 cardboard to make one, put 3 up to bottom on the left and right and then just put 3 cardboard up to bottom in the middle
Cardboard Money : you can get Cardboard money from using the cardboard phone and clicking money
Un-Magicifier : Un-Magicifier is a new block that can be crafted by surrounding 1 magical cardboard with 8 iron ingots and replacing the top middle with redstone, it can turn magical items into normal items and gives you the new…
Magic Spark : which is a new item that if you put any normal item that DOES have a magical version in the third slot of the smithing table and putting the Magic Spark on the 2nd, you can turn it into a magical one again!
Cardboard Steak : Cardboard Steak is a food item that can be traded with the butcher when he's still novice (Tip: you can't really digest it)
Cardboard Apple : Cardboard Apple is a new food item which can be crafted by surrounding an apple with 4 cardboard on the edges (Tip: you still cannot digest)
Cardboard Coffee : Cardboard Coffee is a drink that gives you speed II when drinked, you can make cardboard mugs and put 1 cardboard mug and one cocoa bean to make cardboard coffee
Cardboard Arcade Game : Cardboard Arcade Game is an arcade machine which does absolutely nothing but looks cool, it can be crafted with 8 cardboard surrounding 1 redstone dust and 1 magical cardboard on top of the redstone dust
Cardboard Cleaner Robot : Cardboard Cleaner Robot is a new mob that cleans up cardboard blocks "kids these days throwing all their cardboard around"
There are also magical items that i'll let you find what they do your self (;
