Perpetua Titling was originally designed for Monotype in 1931. From the 1930s to the 1950s (the last days of metal typesetting) Perpetua Titling proved very popular for contrasting headlines. You can easily find books from that era that were set with Times or Baskerville body text and Perpetua headings. Because they have been designed to be used at large point sizes, both Perpetua Titling MT Bold and Perpetua Titling MT Light look best with extra space between the letters. Consider increasing character spacing so these fonts do not look too tight.