Investors with an interest in Medical - Products stocks have likely encountered both Envista (NVST) and Boston Scientific (BSX). But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.There are plenty of strategies for discovering value stocks, but we have found that pairing a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system produces the best returns. The Zacks Rank is a proven strategy that targets companies with positive earnings estimate revision trends, while our Style Scores work to grade companies based on specific traits.Envista and Boston Scientific are sporting Zacks Ranks of #2 (Buy) and #3 (Hold), respectively, right now. This system places an emphasis on companies that have seen positive earnings estimate revisions, so investors should feel comfortable knowing that NVST is likely seeing its earnings outlook improve to a greater extent. But this is just one factor that value investors are interested in.Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its current share price levels.Our Value category highlights undervalued companies by looking at a variety of key metrics, including the popular P/E ratio, as well as the P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that have been used by value investors for years.NVST currently has a forward P/E ratio of 22.83, while BSX has a forward P/E of 27.06. We also note that NVST has a PEG ratio of 0.87. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. BSX currently has a PEG ratio of 2.90.Another notable valuation metric for NVST is its P/B ratio of 1.85. Investors use the P/B ratio to look at a stock's market value versus its book value, which is defined as total assets minus total liabilities. By comparison, BSX has a P/B of 3.86.These metrics, and several others, help NVST earn a Value grade of B, while BSX has been given a Value grade of C.NVST stands above BSX thanks to its solid earnings outlook, and based on these valuation figures, we also feel that NVST is the superior value option right now.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Envista Holdings Corporation (NVST): Free Stock Analysis Report Boston Scientific Corporation (BSX): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research