The red wavelengths of light are the longer wavelengths and the violet wavelengths of light are the shorter wavelengths. Between red and violet, there is a continuous range or spectrum of wavelengths.
The USPS also includes that a large postcard is 49 cents to mail. The maximum size for this postcard is 11 1/2 inches long, 6 1/8 inches high and 1/4 inch thick. This is the same rate to mail a First Class 1 ounce letter domestically. The rates for postage increased as of January 2014.
If youâre mailing a postcard domestically, the First-Class Mail rate is only $0.35. This rate is for a postcard that has a maximum size of 6 inches long by 4-1/3 inches high by .016 inch thick (i.e. the types of postcard usually sold in stores catering to tourists and college students).