Glass and metals. 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 5 to 7 times before losing quality while plastic can often be recycled 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.