Other designers seek out her expertise regularly. For instance Christien Meindertsma, Claudy Jongstra.
Between 2004 and 2009 she produced all dyed artwork for Claudy Jongstra.
The textile staff of the Gerrit Rietveld Academy participated in classes with Leentje. In their textilelab they use her printpaste recipes.
For years she was intensive involved with the start and product development of Rubia NC.