Rosin is an extract that is gaining in popularity because of its simplicity. All it takes to make rosin is some heat and pressure. What results is a product that is clear and has the consistency of tree sap. There is no risk of leftover solvents in the rosin, as no solvents are used in the extraction.
Although rosin extraction is a relatively simple method, it still yields some great potent results as it is a concentrate (although it may not be quite as strong as some of the concentrates produced by extraction methods). One of the most desirable features of rosin smoking is that you know that no solvents were used in the production, therefore all you will inhale is the pure enjoyment of high-quality cannabinoids.