I spent the majority of my life believing that in order to do anything with knit fabric, one needed a serger. Turns out, a regular sewing machine can actually work better for many knit projects! While using a twin needle gives the best finished effect on hems, you can accomplish a simple side seam alteration on a knit top with just a zig-zag stitch and basic sewing skills!
I was badly in need of a brown tank top, so I took a look around at Goodwill. To my delight, I found a liz clairborne tank in good condition for just $.99! (It's a little thin so it needs to be layered, not the most ideal for a tank top, but for $.99 it will more than do the job until I can get/make something better).
I am pretty curvy, so an off-the-rack top often doesn't fit me very well. This means that when I'm buying secondhand clothes, I deliberately look for something a size big, so I have plenty of room to work with for altering the side seams.
All I did was put the top on my dressform and pin the sides as I wanted. I was just careful to make sure they didn't wrinkle. That's all.
If you don't have a dressform, You can pin it using yourself as a model. Use safety pins instead of straight pins, and get someone to assist you in making sure it doesn't wrinkle.
Then what you are going to do is set your machine to a very small zig zag stitch. I had a width of 1.5 and a length of 2.5.
You can mark your stitching line if you'd like. I tend to just sew and pull out each pin slowly as I sew up to it, as you can see above.
Do NOT trim excess fabric yet. First you need to try it on and check the fit.
Don't freak out if it doesn't fit perfectly the first time you stitch it! I had to make an adjustment on this top, as there were these weird bulges right at the bustline.
Thankfully it was pretty simple to just sew a straighter curve and eliminate the bump.
And here we are, a well-fitting and good quality tank top.
Just what I needed to wear to an outdoor wedding in June!
Now it is your turn! I dare you to pick up something knit and tweak it to fit you better - I think you'll be surprised at how easy it is!