As a voice for the OCD end of CB, (there are more of us than you think, haha!), I have to say that the truly
perfect PB&J is thusly constructed:
J.J. Nissen's Canadian Brown Bread, (not
remotely like the brown bread served with beans, but a butter-top loaf with a hint of molasses), one half spread with Welch's Pure Grape Jelly, the other half spread with Jif, (I prefer Crunchy).
Make sure both are spread evenly to the edges, and clean/rinse knife in-between, (to avoid cross-contamination), and then join by placing the PB side on top of jelly side, (the key is not which is put on first, but putting each on it's own half of bread).
Flip sandwhich over, (jelly side up), slice diagonally, and serve with Lay's Original Classic, (or Cape Cod Kettle), and a cold glass of milk.
Voila ... bon appetit!