Our flat card in cover weight fits in our #10 open end envelopes, this slender design is perfect for a quick note or a unique invitation. In gravel, the consummate urban color. Dark, dirty and complex, gravel looks great with black. Size - 3 7/8" X 9 1/4" Sold in packs of 25 When designing, remember that darker colors may rub off on lighter colors. Consider using a layer (such as tissue) between the different colors.