Abstract: 100-800 nm ReBCO films with critical current density (Jc) values in excess of 1 MA/cm2 were fabricated from aqueous nitrate precursor solutions with additives. Additives such as polyethylene glycol (PEG) and sucrose were selected to suppress crystallization of barium nitrate. This produces higher concentration solutions resulting in thicker crack-free single layers. Additional water-soluble viscosity modifiers, such as polyvinyl alcohol (PVA) or cellulose-derivatives, were used to increase thickness and allow wetting of ceramic surfaces. Water vapor present at higher temperatures during heat-treatment damaged the films, while the role of water vapor at lower temperatures is still under investigation.