Consider that the baitis a total of 3 3/4" long and you can cut the skirt to whatever length you want. I cut mine back to either 3" or 3.5 typically.
If you cut it back to 3" that's half tube and 1/2 tail....thus the 3" tube.
If you want a thicker tube I dip them (often just the head to slightly after the hook eye) in a darker color....or the same color if you prefer the bait to be all one color.
Another cool look is to hand pour the bottom of the tube to give the "belly" a different color. I like an orange belly and a watermelon brown/red flake upper body and tail.
You can also shoot the entire bait in one color, the trim off the body just barely ahead of the tail (keep the tail on the spline), reinsert and shoot a different body color. (Like the one in the mold picture).
This is also why there is just a skirt mold..shoot the skirt mold and then put it into the tube mold. This also works with skirted chub grub molds.
