Factors such as paint damage, stretched metal or an already re-painted panel can inhibit the success of a PDR repair.
While putting that material back is generally unlikely, tech and industry advancements have shown great strides in fixing damage that was previously believed to be irreparable via PDR.
Glue pulling, tension methods and power boxes have opened the realm for even deep stretched dents to be repaired to as close to factory spec as possible.
Almost 30 years later Oskar Flaig made the first public display on record, in February 1960 during the "International Motor Sports Show" in New York City, USA.
At the trade fair in New York City, Oskar Flaig used a hammer handle to push out a small dent, so he would need to apply less filler before painting.
After the show, Flaig returned home to Germany and started developing techniques and tools to repair dents.
[2] In other forms of metal working, similar techniques of paintless dent removal may have been employed as early as the 1930s in automotive assembly plants.