Dave...I do know that you can print plastisol on water-based, but as far as I know, you can't do the other.
I may be wrong....but I don't think so....or maybe I am...usually not...but then again.....
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__________________ At the edge of our dreams lay the ideals of true creation.
if you print the base with plastisol why overprint waterbased ink on top of it? since you started with plastisol why would you change inks for an overprint? if you want the soft/ no hand feel your not really going to get it as much with overprinting on plastisol. Fluid said you can attain a soft feel with plastisol but if you are overprinting it is going to be less soft. If opacity is the issue just use plastisol. If it's the feel you really are concerned just go waterbased. combining the two defeats the purpose, at least thats what I think.
Better git ya some red plastisol Dave. Your going to open a can of worms by puttin water-based on plastisol.
The reason you can print the other way is that, water-based will absorb into the fabric and let the plastisol grab some fibers as well. Plastisol will grab all the fibers and the water-based will float on top, not sticking to the plastisol.
Your better off printing the red water-base, then flashing the color and reprinting it until it is red. Be careful not to get a bullet-proof print if you do.
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__________________ At the edge of our dreams lay the ideals of true creation.
I do not think waterbased inks will adhear to plasticols. It may dry correctly yet a wash will result in a white print.
If this is for a client dont be cheap. If its your own line even more so. remember your name is on those shirts and if they leave your shop your name may be mudd.
plastisol/water based ink question 
