Ila,
I'm a many time Sew-Classic customer. Good place to spend much money.
I bought some of those stick on graduated stickers, put one on my HOTHER machine (avatar pic) and found it all but useless for me.
Even with the graduated marks I could not keep the seams straight. Also after a while the fabric began to curl the sticker at the leading edge.
So I went back to the screw on fabric guides. Those stickers are a waste of money in my opinion. Of course YMMV.
Joe