Liberty Cap Large Cents were struck on planchets from various sources, so the weight, thickness and diameter can vary from coin to coin.
From 1793 to 1795, cents were struck on thick plancets with a weight of 13.48 grams (208 grains). Some issues of 1795 and all of 1796 were struck on thin planchets with a weight of 10.89 grams (168 grains). Those struck on thick planchets had a lettered edge, reading ONE HUNDRED FOR A DOLLAR, followed by a small leaf. The cents struck on thin planchets had a plain edge. All had a diameter of 29 millimeters and were struck out of pure copper.
Some issues of this type (1795 mostly) were struck on tokens of British origin, and various edge varieties are also known. Most planchets were usually imported from England by ship and many planchets show corrosion, the result of a chemical reaction after exposure to sea water. Production quality varies, with many showing weakly struck devices, primarily for the examples struck on thin planchets.
taken from: http://libertycaplargecent.com/