I do it all the time. Especially with the invisible thread when I want a strong stitch but don't want to add any color to the quilt or wallhanging tops. I have a 10 spool thread stand that sits directly on my Babylock. I place the two spools side by side and thread both through one thread hole on the stand and I tie them to an existing strand of thread already threaded on the machine. Then I guide the thread through the machine, snip off the knot and single strand of thread, and then hand thread the 2 invisible threads through the needle. When using the invisible thread, I use a 90/14 needle when quilting and binding quilts and a 80/12 microtex sharp needle when making wallhangings using very thin batting. I have a huge amount of Tex 24 poly cone thread (3-6000 yds) that I double up also. My Babylock loves it and I don't need to touch the tension. I have the Babylock Ellegante BLG and the Babylock Jane. I do this for both machines without any problems. I mainly use the Tex 24 threads in the bobbin, and I have used Maxi lock, poly thread from ThreadArt, and poly embroidery thread just fine in the bobbin. I have so much poly thread that I have not invested in any cotton thread.