You should use the thin glossy magazine paper, along with copper plate rubbed with sand paper and washed with acetone or citric acid to remove any moisture on it then you should heat the copper plate for about some seconds say..50-60 and then put your print out down,Also use the LASER JET printer's only or the photocopier print out's only and note to keep the PCB STRAIGHT (or else the print inside would get on board and the sidelines will remain)