Multi-coat painting process

A process for producing a multi-coat lacquering on a substrate provided with a stoved first electrodeposition lacquer layer, comprising:

• applying a second coating layer corresponding to a dry layer thickness of 10 .mu.m to less than 30 .mu.m comprising a first water-based, colour-providing and/or effect-providing base lacquering agent which contains one or more polyurethane resins to the first electrodeposition lacquer layer;
• applying wet-on-wet, a third coating layer corresponding to a dry layer thickness of 7 .mu.m to 15 .mu.m, comprising a second water-based, colour-providing and/or effect-providing base lacquering agent;
• applying a fourth coating layer comprising a clear lacquer coating agent to the third coating layer without prior stoving;
• and
• stoving the second, third and fourth coating layers together
• wherein the first and second water-based base lacquering agents contain the same or different polyurethane resins;
• wherein the first base lacquering agent has a higher concentration of polyurethane resin than the second base lacquering agent, with respect to total weight of the respective water-based base lacquering agent;
• and
• wherein solid resin content in the first base lacquering agent differs by not more than 20% from an absolute value of weight of solid resin in the second base lacquering agent.