This 2D image shows a test section of painted wood from the Horten Ho 229 V3 before it was cleaned. Conservators used a one by one centimeter section to test different cleaning methods. This section was eventually treated with a solvent gel formed from a 5% mthyl cellulose solution in de-ionized water, with a small amount of Triton X-100 non-ionic surfactant and Ethanol added.  Image: Lauren Horelick, 2014