Ztwelve principal Heidi Karl has designed beautiful and effective projects for organizations of every size, including emerging startups, regional powerhouses and nationally known entities.

Educational Institutions

  • Agnes Irwin School
  • Cabrini College
  • Colligium Charter School
  • Drexel University
  • Drexel University College of Medicine
  • Educational Testing Service/K-12 Center at ETS
  • Franklin Institute
  • Lower Merion School District
  • Mastery Charter Schools
  • Penn State Abington
  • Rodel Foundation of Delaware
  • Rosemont School of the Holy Child
  • Sacred Heart Academy- Bryn Mawr
  • School Lane Charter School
  • University of Pennsylvania Museum of Archaeology and Anthropology
  • University of Pennsylvania: Penn Libraries
  • University of Pennsylvania: Wharton School
  • Ursinus College
  • Valley Forge Military Academy & College


Health and Medical

  • Bryn Mawr Orthodontic Labs
  • Ilera Healthcare
  • NMR: Natural Medicine and Rehabilitation
  • Premier Pain Doctors
  • MHC: Mental Health Consultants


  • Delaware County Children’s Advocacy Center
  • Legacy of Love
  • NewCourtland Senior Services
  • Philadelphia Corporation For Aging
  • Rodel Foundation
  • United Way of Philadelphia and Southern NJ
  • Women’s Humane Society



  • Berman Voss Law Firm
  • Comcast
  • Eastern Technology Council
  • FORT Robotics
  • Linode
  • PACT: Philadelphia Alliance for Capital and Technologies
  • Philadelphia Bar Association



  • Cache
  • Drexel University College of Medicine: Alumni Magazine
  • Home & Design
  • MetroKids
  • Modernism
  • Style 1900