Cellulose, the primary component of paper, is a biodegradable, renewable, inexpensive, biopolymer, which is abundantly present in nature. However, the hydrophilic nature of cellulose restricts its use in a number of important industrial applications. Hydrophilic cellulose surfaces often need modification to allow tailoring of surface properties for specific applications. For example, a hydrophobic surface is required for packaging industries, while a controlled hydrophilic surface is required for printing industries. This work focuses on surface modification of paper substrates by glow discharge or plasma processing to create tunable and controllable surface properties such as hydrophilicity, hydrophobicity, roll-off-superhydrophobicity and sticky superhydrophobicity. Microscopic observations of the interaction of liquids with these functionalized cellulose substrates are also performed with high spatial and temporal resolution, thus providing a detailed view of the interaction of liquids with functionalized porous substrates.