First and second elongated flexible insulated substrates have patterns of resistive liquid level sensor sections along the substrate lengths, each pattern comprising printable resistive ink of the same resistivity (ohms-squared), wherein the patterns can be simultaneously printed upon each substrate to save manufacturing costs. The substrates can be separated by an elongated spacer that couples longitudinal edges of the facing substrates together with an appropriate adhesive. Alternatively, the facing substrates can be folded along a central fold line to form a first longitudinal edge and adhesively joined along a second longitudinal edge opposite the first longitudinal edge. The flexibility of the substrates enables the low manufacturing cost liquid level sensors to be positioned in for example in a highly irregularly shaped vehicle fuel tank. Also, sections of varying lengths to be cut from the rolls on demand by users to form customized lengths of liquid level sensors for numerous applications.