Joining and creating a pattern at the same time

I am knitting a wrap that is knit in two pieces joined at the center back when finished. Both pieces have live stitches (not caste off) on them at this point. Does anyone know of a way to create a bit of lace pattern between the two pieces and joining them together at the same time??? It would be a form of three needle knitting I think! Point of it would be to create a creative line of 1 to 2 inches wide down the center back instead of a seam line. Any ideas would be most welcome. Thanks.

I think you would have to pick up one set of live stitches, make your design, then join the other set of live stitches when you BO.

Depending on what your pattern is, grafting may give you an invisible join without a seam. You can see a video of grafting or Kitchener st on the Free Videos tab at the top of the page, under Tips, Seaming, Kitchener st. Also Google Kitchener or grafting and other demos will come up.

You could knit 1 or 2 inches of a symmetrical lace design that started with just a knit row on to one of the sides and then use kitchener stitch to seam it to the other side. The kitchener graft would create a matching knit row on the other side so it would look like the centre was in the middle of the lace you did and not where you seamed it together.
You could also add a bit of lace to each side and then graft them together to get a row of knit stitches all down the very centre.
I don’t know of a way to graft/bind-off that would get you a lace pattern as you do it.
Good luck!

Thank you all for your suggestions! I am just about finished the second half of this shawl and am going to give Mouser’s suggestion a try. If It doesn’t work for me I can always graft it to give it a satisfactory seam down the back. Does anyone know where to look for a Celtic type lace pattern? I would have to be able to work it vertically.
Thanks again.

Could you find your xx wide lace pattern, then when you get to the end of the row, k2tog using the last stitch of lace and the last stitch of the side piece. On the next row, at the end k2tog using the last stitch of that row and the last stitch of the other side.