In using a guitar amp, it's important to know how to manipulate the amplifier to achieve a number of different effects, including a clean or dirty sound. Learn about using the bass and treble knobs on an amp with help from a professional guitarist in this free video on guitar amps.
A 10 X 13 envelope (must be less than 1/4 inch thick) is considered a flat and costs 80 cents for the first ounce and 17 cents for each fractional ounce after that up to 13 ounces.
1 Large envelope-sized pieces that are rigid, nonrectangular, or not uniformly thick pay parcel prices. 2  For keys and identification devices, add $0.83. 3  If more than 13 ounces, see Priority Mail (footnote #4) on page 3. 4  For weights over 3.5 ounces, see Large Envelopes prices.