DMC 646 to Cosmo: Thread Conversion

Cosmo 161 is a close match that tends slightly cooler, with more gray and less beige than DMC 646. For most fill work in the upper-shadow zone, this difference is irrelevant. When 646 is specifically serving as a temperature bridge between warm and cool palette sections — as in wildlife designs that transition from warm-brown earth tones to cool-gray sky — the cooler Cosmo 161 may shift the blend slightly. Test in context for critical applications.