Blocking clothes extension is something that can be used to increase the size of clothes. If you have a tee shirt, dress or trousers that are too small, a separate panel can be added in a contrast colour. I am in the process of using blocking to increase the size of an animal print jacket a friend bought me. It was the only size, but was too small, so I purchased some black fur and will create sections to the side back panels beginning at the armhole, and I will unpick the top section of the sleeve and place a block down the top of the sleeve.
Another example is the photo on the right where a dress has blocking in black down the sides. The dress below it has been designed this way, however it could easily be done with a dress that is too small by cutting across the front and back and inserting another colour.
Blocking is a great way to redesign clothes.
Happy altering