After my first attempt of putting an invisible zip in my first skirt i attempted it again using the right foot on the machine and it worked out really well and was actually invisible. However once i put the skirt on the model and zipped it up, the zip broke i think it was because the skirt was small fitted so it was difficult to get the zip up and we tugged on it to hard.

Overall i think my second skirt worked out a lot better than the first because i understood the places i had gone wrong the first time.

http://www.sewbox.co.uk/blog/235/how-to-sew/a-beginners-guide-to-interfacing/

I wanted to learn more about interfacing and how it can be used and what fabrics its best for etc and found this blog which was useful on giving information about it.