Hi Bob, the Hardwood Exterior Penetrating Oil Finish is made with Brazilian rosewood oil whereas the Architectural Grade Hardwood Finish is made with an alkyd-urethane hybrid. The Hardwood Exterior Penetrating Oil Finish requires paint thinner or mineral spirits for clean-up, whereas the Architectural Grade Hardwood Finish can be cleaned up with soap & water. Due to the ingredients, the Architectural Grade Hardwood Finish cannot be shipped in the winter months. The data sheets for the [Hardwood Exterior Penetrating Oil Finish](https://penofin.com/pdf/ds/DS-hardwood.pdf) and the [Architectural Grade Hardwood Finish](https://penofin.com/pdf/ds/ds-penofin-architectural-grade-hardwood-technical.pdf) are very helpful with comparing the two.