Well, after six weeks of some very detailed piecing, it's finally time to start assembling our large blocks! Now, while we've had very few seams to line up so far, there are two places on this block where seam intersections are very important.
First up, the A Block corner should come into to perfectly line up with the edge of the B Block diagonal. Now, in a perfect world, this should just happen when the two blocks are sewn together ... but in reality, you'll probably need to give them a little help.
My trick for getting these pieces to kiss where they're supposed to is to stick a pin a 1/4" in from the edge of stitched diagonal line on the B Block. When you put it right sides together with an A Block, the pin needs to continue right through the print/solid seam, 1/4" down from the edge.
Don't worry if the top and bottom of the blocks are a little off - you can fudge those later. The important thing is to keep these two intersections perfectly aligned. Then, when you go to stitch the block together, your seam should go right through the place where you had the pin.
98% of the time, you'll get a perfect match. Sometimes things can still be a smidgen off, but you can decide at that point whether it needs to be re-sewn, or if it's close enough to call it done!