Silver Metallic Plastic Mulch 4 Ft X 600 Ft 1.0 Mil Embossed By Growerssolution Silver Mulch has been University proven to increase yields up to 20 percent and lowers insect problems. Silver Mulches reflect sunlight up into the undersides of the canopy, thereby increasing photosynthesis, leading to rapid growth Both harvest yields and coloring of fruit increased with Silver Mulch. The extra light from the reflection repels insects and the increased light from reflection is one of the reasons your yields increase. Silver on one side black on other.