Though recycling waste is better than sending it to landfill, it does not mean we can recycle it forever. After a number of cycles, some materials will start to lose quality. Paper can be recycled five to seven times before losing quality while plastic can often be recycled only once or twice. Glass and metals, such as aluminium, can be recycled indefinitely without a loss of quality. This is cost effective and less energy intensive as manufacturers do not need to add more virgin materials.