MAKING THE RIGHT CHOICE
It may be that there is a performance level you choose every time – SPX, SP or P – or you might prefer to choose a color based on a given situation. For instance, you will maximize the productivity of experienced workers with red SPX inserts, but you might want to stick with black SP or gray P inserts for your novices, at least until they prove their skill on the job.
Your decision might also depend on the nature of the job itself. Where high performance is required, you might always reach for red, but black or gray may be sufficient where other factors come into play.
