LOL .... er ..... define "realistic"?
I actually did this, had several tries at it with varying degrees of success.
I made a pair of boobs as moulds ( out of auto body-filler and a lot of patient shaping and sanding ) then coated them by repeated dips in liquid latex and filled them with glycerine 'cos it was pre-internet and I couldn't find any suitable silicon.
I used acrylic artists paint mixed into the latex to colour the outer couple of dips to match my flesh-tone.
The results were pretty good and could be glued onto the body and worn which was felt fabulous to me.
I had higher aspirations though and amongst other things wasn't happy about the "blend contour" onto my own skin around the edges.
For the next attempt, I used the boobs I'd already made ("male" moulds) to make "female" moulds so that this time I poured the latex into the cup-shaped mould and swilled it around.
In both versions I also left a "tunnel" through from the nipples down to my own nipples which I had pierced and rings put in so that there could be a connection to transmit movement etc.
Whilst the transmission of movement from jiggling etc felt really good, there was then a problem with the rubber nipple-to- real nipple connection pulling the outer skin of the prosthetic and making it dip in when the breast-forms swung from side to side.
I had a plan to solve that problem in the next version, where I also intended to include some electronics to give some sort of touch sensation from the outer surface of the rubber breast onto the inner surface which sat against my own chest.
...er..... I should mention at this point that I'm prone to be a bit obsessive
That last project was abandoned halfway through, when I'd got as far as to cast the outer skin(s) complete with embedded fine gold wires........
But by then, I'd cracked up and finally accepted that I was TS and the only way to ever get even close to what I wanted was to damn-well grow my own!
Jeez. ....... the amount of time, money, thought and effort I put into the whole Falsies project.
....and that's just the bra region...... I experimented with similar ideas in the panties area too
(For the technically curious:-
I zoned the loops of wire (aerials) in the outer breast surface and I zoned the wires in the back of the breast which sat against my chest. These latter wires were stitched through, so that they made electrical contact with my skin.
Each breast housed an always-running impulse unit, based on a simple TENS unit that my ex had for back pain.
The intention was to use the hum-field proportionally induced by varying degrees of contact with the outer skin to route/regulate the TENS output to the appropriate skin zones.
I had the bread-boarded circuitry working quite well in principle, though I had to cut down my original grandiose plans to only 5 zones because the physical size of the circuitry and the power drain was getting out of hand!
To make the electronics small enough, I was just soldering tiny components across the chip pins and together in a rats-nest to be encapsulated in epoxy.
It was a workable idea and could have been completed eventually, but finally acknowledged that just taking estrogen is SO much simpler and gets PERFECT results. )
