I started using that fusible tape, but I found that if the edges aren't perfectly straight I ended up with little gaps with no batting in some places. And once it's on, it's on! I don't think it's worth the cost to me to continue using it. Unless I would happen to have a show quilt someday. (!!!)

Before that I used Elmer's glue stick and stuck the pieces together. It sets up pretty fast. Yeah, there's a tiny overlappy ridge, but after the quilt is done and washed it's not bothersome to me. I've even glued multiple chunks together to make the big batting piece.

Before the glue I hand basted with big stitches.

I bought fusible interfacing when Joanns had it for 49 cents a yard (a whole bolt) and cut my own strips to try putting batting together, worked great. I used to zigzag but may do this all the time now as that was pretty cheap and easy!!!

I just cut strips from the Pellon lightweight fusible you get at the chain fabric store using a coupon. Doesn't take any time to cut the strips because accuracy isn't required.. I overlap the pieces to cut so I have an excellent tight fit. I have felt the bulk from the zig zag in a quilt and this method allows no different in the feel of the quilt.

I cut light weight fusible interfacing into 1.5 strips and use it to iron the pieces of batting together.

I lay two leftover pieces of batting on top each other and use the rotary cutter to cut them to be sure they are straight and then butt them together and zizag them together. It works great and is almost relaxing! froggyintexas

This is what I have started doing. I cut my tricot into strips and iron the batting just like the tape. Even better I buy it at 50 or 60% off at JoAnns.

A long whip stitch is about all you're going to need. The quilting will hold everything in place.

I piece batting all the time. I lay the two pieces with a little overlap and cut them so the edges are exactly the same and either whip stitch them together by hand or zig zag on the machine. There is no ridge where they are joined and I've never had a problem with the finished product. I haven't used the tape because once I looked at the price I didn't want to go there.

I have tried the fusible but it doesn't want to stick very good so I like to zigzag which holds the pieces together

I use batting pieces all the time. I spray baste my backing fabric and gently place the batting pieces on it, carefully meeting up the seams. Then I spray baste and place the quilt top. I do FMQ and this works fine for me. Instead of basting tape, you can cut strips of knit fusible, it is the same stuff, if you want to go that route. And I have never noticed a problem when laundering!