pet is the most recycled material on the plastic packaging market. this enables the reuse of recycled pet in packaging and fibre applications. the markets of milk packaging, home and personal care are planning to progressively switch from hdpe to pet for cost, marketing and sustainability reasons. these products are typically packaged in colourful containers due to marketing reasons. this market shift could bring about more than 300,000 additional tonnes of coloured pet, including black and white colours. the pet recycling markets cannot afford to absorb these extra colours. if collected and sorted together these numerous coloured containers will need extra sorting in the pet recycling plants.in order for recyclers to sell this coloured fraction, the material will have to be tinted in black or grey, but no market currently exists for such a material in high quantities. even worse, white pet producers may argue that due to a size effect their products can be separated. unfortunately, our data shows that if pet milk bottles contain tio2, the recyclers&rsquo end product will be highly contaminated. for example, the transparency of clear recycled pet will be reduced i.e. haze affect, whilst coloured recycled pet will have tio2 up to 5 i.e. this material will have serious issues for food contact and fibre applications. in both cases this will lead to a fall in the use of recycled pet on the market. these &lsquocolourful&rsquo future trends will weaken the image of pet as a recycled product. additionally, it will create great difficulties for the pet recycling industry, which already has other market barriers to overcome.furthermore, the existing hdpe recycling industry, which already has a market for coloured hdpe applications e.g. the pipe industry will suffer if coloured pet continues to grow. the actors willing to pursue this dangerous path should be ready to bear the increase in epr costs and accept a collapse in the pet & hdpe recycling industry. a solution could be to use full body sleeves which would ensure a colourful effect. nevertheless, these sleeves must be detectable by nir sorting systems and cannot interact negatively in the recycling process. pre calls on the pet and hdpe value chains to join efforts to avoid breaking the circular functioning of these recycling streams.