Resawing is the act of cutting a board down the middle to get a thinner board. I've used this to make "bookmatched" doors or boxes. Bookmatched simply means that the grains of the 2 boards match each other - they are mirror images (almost). This is a good way to make boxes that have the grain of the wood running all the way around the box and matching up. The picture of the 2 boards shows how a resawn board looks after the process is complete - this is the board I used for this instructable.

Step 1: Size the Board Width

In order to cut the board down the middle you need to find the middle of the board. There are several ways to do this - I simply use a a square to determine the width and then find 1/2 of it. I set this to the middle of my table saw blade from the fence. The image for this step is the

Step 2: Cut Into the Board

In order to get a cut into the board there are things to remember
1. Cut one side, then flip the board and over so you keep the same side of the board against the fence
2. Cut in multiple steps - don't try to raise your saw blade to maximum height and cut it all at once. I tend to cut in 1 inch increments

I use a feather board to help hold the board firmly against the fence. When you are done with this step you have a board with a cut on each side and wood still in the middle

Step 3: Clamp and Make a Starter Cut

I clamp the board in a woodvise so that it is tight - it is a good idea (though not pictured here) to clamp boards in front and behind the board to be cut to help stabilize it.

In order to cut the board safely using the sawzall it is necessary to have a starter cut. I use a hand saw to cut this and make it about 3/4" deep

Step 4: Make the Cut With the Sawzall

Use the sawzall to cut the middle - I've used both fine tooth metal blades and rough blades for this and both have worked. The key is to have a blade that is long enough to make the cut - I use a 9 inch blade. Place the blade in the cut you made with the handsaw and slowly begin cutting the board down the middle. The sawzall speed can be controlled with the trigger, so decide how fast or slow you want to go. Don't force th blade down, but rather allow it to cut and keep it steady with a firm hand and downward pressure
You will only be able to saw partway through the board and then you will have to flip it over and repeat for the other end

Step 5: Remove the Pieces From the Clamp

Pretty self explanatory - the board is cut in half. You can see where the 2 pieces have been cut by the saw and by the sawzall

Step 6: Plane the Pieces

Plane the pieces to consistent thickness and enjoy the look of the bookmatched boards. These would be great for door panels and will give you the width you need without paying extra for it to be done for you