True colloidal silver is filled with mostly nano-particles (not ions), thus providing the optimum active surface area per unit of silver, and has a light golden color.
EIS is a clear silver solution mostly filled with ions (not particles), which results in a lower health efficiency value per unit of silver than in true colloids. The difference between true colloids and solutions is very well explained in the article following: http://www.silver-colloids.com/Reports/reports.html?partner=37
