I think you got the answer, but it is recommended to use same thread in the bobbin. You want the lace to be idential from both sides. Try something small both ways, and got with your choice. A sample would not hurt.
Thank you. There have been such beautiful FSL on the project page using varigated threads that I want to try it.
I do both. I think it's a matter of preference and the varigated thread color. I have one that is yellow to white and have used white bobbin thread with a very nice effect.
Absolutely use the same in both places. You want your lace to be just as pretty inside as outside. The only reason that I could think of not to is if you are using a varigated that goes toward white as in ecru, then that might be pretty and interesting.;)
I have so far used same thread in the bobbin as spool when doing FSL. You don't have to worry about tension of one or the other being off slightly and seeing one color on both sides. i.e. you see my FSL bowl and nutcup in varigated in projects? Also check Shirlenes nutcups, tho not using varigated, you see the color on both sides very easily. *4U
I have done it both ways. It really depends on the effect you want to achieve. If the item will be seen from both sides I'd use the same thread in top and bobbin. That way it will look close to the same on both sides. If you use white in the bobbin, or any solid color it will look completely different on either side. Maybe that's the look you want for some items. Hope this helps.