You will not generally infringe copyright by selling an item such as a coat hanger made from Bananas in Pyjamas material you purchased, or a play suit or cushion made from material which the manufacturer printed with The Simpsons or The Muppet Show designs.

However, you may need to consider other areas of law if your item looks as if it is authorised merchandise. If this area is of concern to you, you should consult a solicitor with the relevant expertise.