When You Make A Pieced Border
 

Do you have to wait until the top is together? I am contemplating piecing the border on my snowman quilt, but I am not sure if I need to wait to cut the pieces and find out the size of this thing.

I wait until the top is finished.

Yes, you will need to know the exact dimensions to do the math for your blocks on the pieced border. You may even need to add a small strip border to the top to get the math to work. Math is my least favorite subject and I often have problems with pieced borders because of this. I *get* them eventually, but it's frustrating (to me).

I have done it both ways.
The point is that the border pieces have to be accurate. There is little 'wiggle room' if it is to fit the body of the quilt. So, your piecing must be accurate as you go. I always measure units as I go just to be sure they are accurate.

i always wait until the main section is finished as it may not come out just as planned

no, I dont wait because the boarder can take as long as the quilt. and, I always have to adjust for length. so I plan on some kind of cheater strip

I generally wait until I'm done with the top regardless of what the pattern says; I'm not always as accurate as I would like to be and would hate to have my borders too big or too small. I only cut out for the blocks and save the border for last.

It depends on what kind of pieced border you're making. Piano keys, for instance, can always be adjusted in size after the exact measurement of the top is known. I never make the border until the center is finished just because I may change my mind about the border when I see the center of the quilt.

What sort of border are you thinking of putting on?