Sewing machine stitches showing good side on wrong side

[PotteryLottery]

I've done some applique using zag zag stitch but the neat stitching is on the underside, not the top side.

Have I somehow threaded the machine wrong?

More likely the tension needs adjusting. Can you post photos of top and underside?

What type of machine are you using?

I used my young daughter's Hobbycraft sewing machine for the straight hem and it looks neater on the underside than the showing side.

I used a Silver sewing machine to zag zag and it looks better on the underside.

Have I misthread the bobbin or needle on both machines? See attached pics

Straight hem pics here

It could be the tension, or you might have misthreaded the machine. I have also had my stitches go a bit crap when I have used really cheap thread or the wrong thread for the job., could that be it?

It's the tension. Fiddle around with it and do some practice stitching on a spare scrap of fabric until it looks right. It looks like you have the upper thread tension too high.

Also check that your bobbin is on the right way round. If it's feeding wrong that will cause the same issue.

How do I know if the bobbin is the right way round or not?

You are going to need to do some trial and error to get your settings right. Thread the machine with the same type of thread as you want to use and find two layers of the fabric or very similar weight and material.

Sort out straight stitches before zig-zags.

Sew a straight line and then remove fabric, make adjustments and sew a new line until you are happy. Let the machine feed through the material, don't try to pull it through like you see on TV. Try sewing more slowly than you would expect as well.

Re: bobbin - turn it over so the thread comes out (anti-)clockwise instead of the opposite.
Re: tension - the upper tension looks too tight. Turn the tension dial (usually on top of the machine and may slight resist being changed) down.

Repeat until you have good stitches. If still too tight, try adjusting stitch length or putting a VERY slight zig-zag on your straight stitch.

Once the straight stitch is correct, the tension for the zig-zig should then be right, but you may need to adjust the stitch length.

Good luck. Once you have it right, photograph to machine if you have little fingers in the house who may like to adjust things.

Look at the machine instruction manual, if you don't have an actual one you may well find it online.

In your second set of pictures, if the second picture shows the stitching from below i.e. from the bobbin then your bobbin tension is too tight or your top tension is too loose.

Try increasing the top tension first, if that makes no difference then adjust the bobbin tension which you may well need a small screwdriver for. Only do small increments at a time and remember to make an note of the correct tension settings when you achieve them.

If the tension keeps going wrong you may have to get the machine looked at by a technician. Is your machine computer aided?

If your bobbin is in wrongly the machine won't stitch at all.

As others have said it's your tensions. The top tension is either too tight or the bottom one is too loose. Top one is usually easier to adjust, so loosen that one and see if that sorts it. If not, tighten up the bottom one.