Mixing thread weights
 

I have 50 and 40 weight threads. Will I screw up my tension if I use one weight in the bobbin and different weight in the needle. I know there are LOTS of thread experts here.... that's why I asking!

I’m not a thread expert but I use 40 wt on the top and 50 wt in the bobbin with no issues.

I don't think it will change your tensions to do so, but you may or may not get as nice a stitch. I've found that most of my machines don't care but one (and I can't remember which one) gave me fits when I tried using different weight threads on the top and bottom

I use 60 and 80 wt thread for bobbin sometimes with 40 wt. Glide and never change the tension.

I always use the same thread on top as I do the bottom....too chicken to try mixing them up...haha

I can tell you for embroidery machines, it's usually 40wt on top and 60wt in the bobbin but I've used both 40wt top and bottom also and never saw an issue with tension. I've also used the 60wt in the bobbin and whatever regular thread wt is for piecing and again, no problems.

A HUGE TY to everyone who responded to my question. Now I know it will be easier to sew somewhat stress free...in my dreams...lol! I have a feeling there were lots of quilters who weren't aware this could be a concern with their sewing. Thank you again.