No not the book store!
I like to finish a lace scarf or shawl with a border. Why? Often when I cast off, especially when there are 100s of stitches I can’t get the cast off loose enough and it restricts the size of the shawl or scarf when I block it. So that I don’t have to cast off I knit a border onto the last row. This means that the entire width of the piece isn’t constricted at all as the border is knitted at the same tension as the shawl itself. The only stitches that are cast off are the ones making up the width of the border.
A border doesn’t have to be fancy, it can be a few garter stitches or it can be ornate lace the only trick to it is always knit the last stitch of the border together with the next stitch on the last row of the piece.
The next thing to think about is the balance of the piece. If you make a triangle bottom up and you add a lacy border to the cast off row, you have lace along the top of the triangle. If it is not balanced by a border around the bottom it can look out of balance. It is common for the bottom border on a triangle to be wider and fancier that the top border.
I realised this when I did a nice simple lace border on the design I am working on. I threw the balance of the piece out completely so now I have to knit a border around the bottom of it.
To do that I will pick up an edge stitch and knit it with the first stitch of the border on every wrong side row. To get around the v at the point I will need to pick up that stitch in 2 consecutive right side rows. The sharper the V the more rows of the border that need to be attached to the stitches around the point.
These photos are before blocking so the stitches are a bit wonky and the lace needs opening up.
I designed and started my lace border for the bottom yesterday, I am picking up the main motif in the scarf and doing a smaller version around the edge and also incorporating the elements I put into the top border.