Why 'Recycled' Plastic (rPET) Color Consistency is a Myth
Marketing teams love rPET (Recycled Polyethylene Terephthalate). It tells a great story: "This bag used to be 5 plastic bottles." But they also love strict brand guidelines: "This bag must be exactly Pantone 286C Blue."
These two desires are physically incompatible. Virgin plastic is clear/white, making it a perfect canvas for precise color matching. rPET is made from a mix of clear, blue, and green bottles. Even after cleaning and bleaching, the base resin has a slight grey or yellow tint.
When you dye this tinted base resin, the final color will shift. A "Perfect Blue" dye on a "Greyish" base results in a "Muted Blue" product. Furthermore, this base tint varies from batch to batch depending on the source of the recycled bottles.
In practice, this is often where Sustainable Branding decisions start to be misjudged. You demand perfection from an imperfect material.
The Fix: Educate your stakeholders. Establish a "Color Tolerance Range" (Delta E < 3.0) rather than a strict match. Or, embrace the variation: choose darker colors (Navy, Black, Forest Green) where the base tint is less visible, or use "Heathered" fabrics which naturally mask color inconsistencies.
