Typically speaking, using regular notebook paper and a single envelope, 4 to 5 sheets of paper can be mailed while staying under 1 ounce. The United States Postal Service charges one stamp per ounce...
Exculpatory Evidence: Typically used in criminal cases, this type of evidence is that which favors the defendant, either partially or totally removing their guilt in the case. In the United States, if the prosecutor or police have found evidence, it is their duty to disclose it to the defendant.
False evidence, fabricated evidence, forged evidence or tainted evidence is information created or obtained illegally, to sway the verdict in a court case. Falsified evidence could be created by either side in a case (including the police/prosecution in a criminal case), or by someone sympathetic to either side.