Marking a Quilt to Trim It Square

I bought a new toy called Quilter's Chalk Line recently.  I always have a hard time when it comes time to square up my quilts for trimming them at the end.  I'm happy to say that this little gizmo helps me a lot. It consists of a plumb line, basically, which you fill with iron-off chalk powder (included), a T-pin, and instructions.

T-pin holding chalk line at corner.

I use my carpenter's square to locate my first corner of the quilt.  A large square quilter's ruler could be used, too.  The carpenter's square is just so much longer, so I like it.  (More things to love at the hardware store!  See previous post here.) Then I put a T-pin into the quilt, and through to the carpet, at that corner point.

I loop the hook on the end of the chalk line over the T-pin, then stretch it down the length of my quilt, using the carpenter's square as a guideline.  Holding the blue part firmly in place, I move the square ruler aside a little bit, then snap the line in the middle to make a chalk line on my quilt.

Faint chalk mark on quilt.

Here I've removed the chalk string, so you can see the faint line drawn.  After this step I simply move to the end of the "drawn" chalk line, position my square, and make another chalk line, till I'm finished with all four sides.