Paper marked with a letterhead.
A portion of text at the top of a letter, identifying the sender and often giving their address etc., used for formal correspondence.
A piece of parchment forming part of a roll.
A flexible or semiflexible covering or waterproofing whose primary function is to exclude water.
A mechanical, thin, flat flexible part that can deform or vibrate when excited by an external force.
A microscopic double layer of lipids and proteins forming the boundary of cells or organelles.