Distinction between sale and work contracts determines when property in goods passes and whether a sale exists. A contract of sale is one whose main object is transfer of property in a chattel and its delivery; a contract for work and labour is one whose main object is performance of work or services rather than transfer of the chattel. The decisive test is whether the work results in something that can properly be sold. Contracts using materials may be (1) composite with sale for price, (2) work where materials are accessory, or (3) work with voluntary supply of materials; only when there is an agreement and passing of title does a sale arise.