High-grade, white bond paper used for printing should be recycled separately from other waste paper. This office paper can be turned into stationery such as envelopes, tissue paper and magazines. Low-grade paper such as newsprint, coloured paper and school exercise books can be turned into cardboard, newspaper and toilet paper. Paper juice boxes and milk cartons are harder to recycle, but some South African companies have the technology, called hydro-pulping, to do it. These paper containers are coated with a thin layer of polyethylene plastic to prevent the paper from getting wet.