I don’t think that @zuikoholic’s ongoing problems are typical. Yes - initially, it can take a couple of tries to get it right, but once a good mould has been struck, it fits with comfort, stability and superior acoustic coupling.
I wouldn’t be dissuaded from moulds by reading one problematic account.
RIC, I have tried basic canal, canal-lock and skeleton molds.
Jim
I would say Jim… that’s not quite correct, RIC custom moulds are in my experience, easier perhaps to make, and nearly always fit fairly snugly with little or no problems… full shell or skeleton shell BTE custom ear moulds can be highly problematic, I don’t know who made the NHS ones, but it was rare to get a set that fitted correctly, you might get one okay, but the other would be bad, or extremely tight fitting, hence I said previously about keeping the good impressions, and just handing them in. I would say, it also depends who’s actually taking the impression, not to mention who is actually making the mould, it’s a highly skilled job, apart from the 3D printer ones! Cheers Kev 
Yes my Audi has, without a positive outcome, that was when we tried the Wesone molds.
Not sure what size the vents are but definitely smaller that 4mm, the current (West one) are smaller than the Phonak. There is some occlusion but I didn’t find it bothersome on the Phonak. The latest set
haver very small vents and they are taking some getting used to.
With domes we had feedback issues whenever we got close to my prescriptive target (based on REM) Phonak P70R aids.
We tried simple custom tips first but they just would not stay in, again the left ear being the most problematic.
Might have to give something like that a try.
Jim
Just got back from the Audi. We played with a few domes and it turned out I just have a wide canal. We found an open done that fits beautifully (after I jamb it in) with no rubbing so far. Hopefully that’ll be the end of my adventure on getting a decent physical fit. We also did a little more tweaking on bringing a few channels down a tad (it’s channels, right? I have no idea how the software works) and cleaned up a music memory setting so all seems good here.
I will keep molds in mind for the future should I ever need one to imprint hearing. It’s interesting to read about different experiences even if not directly applicable. I like being better prepared for the future as you never know what’s next.
On my older aids I had the back-out problem. I think it was caused by the wires being a little short. My newer (*but still old KS7’s) have longer wires and they stay in. (I have closed domes.)
The wire length isn’t my issue, my left ear mold/ITE aids have always slipped the slightest amount with even moving my jaw, or bumping my earlobe. When I look at the ear molds/ITE aids I believe it has to do with the shape of my ear canal. My right ear mold/ITE aids have never be an issue.
I trialed a pair of Phonak Marvels last year and the molds were the C Shells, which are a 3D printed mold.
It was acrylic, but fit like a glove.
I preferred the sound of Oticon, so went to the ON S MiniRite, and the 1st 2 pairs of molds had the same issue, the left would slip, and occlude.
They finally came up with the same design as the Phonak C Shells, and are great, so check if you’ve had C Shells, and I understand Phonak offers a Titanium mold that may help ( $$$).
Could you please post a picture. My search turned up a confusing range of possibilities.
This is a screen grab from Dr. Cliff’s you tube video:
The image on the right is the titanium cShell.
Thanks for the picture …
So, then, I guess that’s what I have? If so, I can concur with your assessment of their performance.
(Sorry, the twitchy site software won’t let me upload my pic.)
[Okay … after 11 tries to upload a pic of my mould, I give up!
Wow, even skeleton molds wouldn’t stay put? Or perhaps they were painful? Maybe some of us need velcro tabs sewn on our ears? 
Oticon calls them “MicroShell”, just about the same.
if your receivers are sealed in the mold, that’s what you’ve got.
@flashb1024: Thanks for the link … mine seem to be called “Micro Shell”.
[My moulds are fitted with 100dB receivers, BTW.]
I have the power shell with canal lock,I am going to ask for a skeleton when I go to the clinic on the 13th of May
Keep in mind if it’s acrylic mold canal lock can break off easily if dropped accidentally.
Something that I will have to deal with, with the power receivers the acrylic ear molds are my only choice. And I now have canal locks and my left mold still will not stay in place, so I would like to have more fuller ear molds
The skeleton molds stay put but the the left one was painful.
Jim
