My experience with Corona Fours is that a good example will run well. A moderately long-stroke keyboard but one that requires little effort to actuate, just about mandating the use of heavy second sheet* for those of us who tend to lead-fingeredness.
Does anyone know where to get old-style newsprint-paper second sheet? I used to buy it by the ream (canary yellow), at less than half the cost of 20-lb. white bond. Just the thing for carbons and first drafts. Now it's gone unobtanium.
* Second sheet: that's the the page behind the page you're typing on. Use it! Your typewriter's strikers will last longer and your work will look better. --Add a sheet of carbon paper in between if you're A Real Writer or, like me in my misspent youth, trying to be.