The 1990 Topps set is truly awesome. It was a sharp contrast from previous releases leading up to 1990, but shared similarities with much older Topps sets such as: 1981, 1975, 1972, and 1960. After going back and looking at this set years later, I became fascinated by the design. The inner border actually matches the team colors (only the outer border is random). This is one of the last bubblegum card sets using the old-fashioned type of card stock.
The 1990 Topps master set contains quite a few add-ons such as: Topps Traded (x132), Topps Debut '89 (x152), Glossy Send-ins (x60), Glossy All-Stars (x22), Glossy Rookies (x33), and Award Winners '89 (x6). The set also contains numerous rookies and early cards for players like F.Thomas, S.Sosa, K.Griffey, C.Biggio, R.Johnson, T.Glavine, G.Maddux, O.Vizquel, R.Alomar, etc.
If you haven't looked through this set in a while, go back and take another look. It's truly a hidden gem in both design and content. You'll probably want to go back and upgrade your existing collection.