Welcome! I know this isn't really helpful, but I do some of all the above. I have used variegated, glow in the dark, and completely different colors in the bobbin depending on the look I want. Usually I use the same thread on both if I am quilting with my regular machine. If I'm using the long arm I use a thinner thread on a pre-filled bobbin.

If you are talking about the machine quilting part of the quilt-making...

If I want the thread on the back to not be visible, I use Superior Bottom Line thread...it is very thin and just blends into the back of the quilt. It is a 60 wt. thread. I then use reg. machine quilting thread on the top, which is usually a 40 or 50 wt.

If I want my quilting to stand out on the back, I use the same machine quilting thread in the top and the bottom. (40 or 50 wt.)

Hello and Welcome to the board :D:D:D
So glad that you joined us!!

DO you mean color or type? I generally use the same weight of thread in the top and the bobbin. The color depends on the quilt. If I work with variegated thread, I usually use the same throughout.

Welcome to the board from Southern California!

Thanks to all of you who gave suggestions as to thread on the top and bottom. I will use some practice as you suggested. Now I have another question. Do any of you use fusible batting? It sounds like a good idea. If so, do you still pin?

I usually use the same type thread in bobbin and top but not always the same color.
right now i'm using varigated rayon thread on top and my usual beige thread on the bobbin.
i use fusible batting or spray basting and only pin the border edges to keep those from coming unstuck while i quilt it.
then i soak the completed quilt in the washer and spin to remove the fusible residue.

Thank you. I bought the fusible battiing and then I got scared to use it. I love the idea of using verigated thread on the top!

Hello and welcome from SW Iowa. Glad to have you here. I use the same in the top and bottom.

I use invisible thread on the top (if I am quilting it) and the colour of the backing on the bottom. When peicing, i usually use the same colur top and bottom.