I use silicone and and XTC-3D and other things that need to be measured by volume and instead of buying a bunch of disposable cheap cups I decided to model one and I used Solutech's "natural clear" PLA so I will be able to see the amounts from the outside. I will put measurement lines on the inside if requested. (I do not encourage using this for any food related products as FDM printing isn't usually food safe.) The cup itself hold almost exactly 100ml at the brim.
Can be done is vase mode, is still watertight.
I used a "clear" filament, which I added XTC-3D to one of the cups (to inside and out) and it made the whole print almost transparent.