I got a request for how I paint Apothecary vials and making them look like they're glass and actually holding liquid. I have a fairly simple method I use that gets decent results I think. This process could definitely be refined if you were looking for something more, but this will get you started for sure.
If you look closely at the picture on the right (can be enlarged), you can see that the vials are still just the grey basecolor at the point the picture was snapped.
Painting the liquid
Once you have the entire vial painted light grey, it's time to add the "liquid" to them. You can pick whatever colors you want. I try and make the ones that are next to each other different colors so it's easy for the viewer to tell them apart.
|Note: Here's the trick to getting and making sure the liquid looks correct. Make sure you paint the top level of the liquid parallel with ground. It doesn't matter what angle the vial is it, the liquid should always remain level with the ground inside it. Doing this will help with the illusion.|
The top picture is a perfect example. The vials are angled, but the liquid inside is level with the ground.
As for the actual painting, I block out my base color and then add a wash to the lower portion of it. You can add a highlight along the top edge of the liquid, but it's not 100 percent necessary. By the time we finish, you'll have other elements painted over the top of it anyway.
If you can get a bit of shadow towards the bottom, that's all you really need.
This part is optional and if you're painting tiny cylinders, you may not even need it. In the picture to the side, you can see that I didn't even add it here.
If the vial is larger or in a more prominent location, you may want to consider adding this step.
Just as we considered our ground level when we painted our liquid inside, we need to consider it for our reflection. Some folks paint it (the reflection) in line with the angle of the vial and others paint it perpendicular with the ground regardless of the angle of the vial.
Painting it in-line with the vial is probably the more accurate approach, but we are able to take some liberties here and there to get something that looks right even if it's technically wrong. Just like I did with the glowing eyes on my Librarian, sometimes it's ok to push things for an effect. One way may look better to you than another so I'd say to go with that one.
Start with your white paint and thin it out some. You want to create a highlight that runs from the top of the vial down the outside edge to the bottom. Painting it in one pass would make it too sharp for this scale. By making a few passes with thinned out paint, you can feather the edges slightly and get a better result.
Of course, that's easier said than done. The key is to make sure you don't overwhelm and cover up everything you've painted up to this point. You want the liquid to show through some.
Again, this is for real quick results on tabletop models. There are a number of things we could do to "improve" on our results here, but the main idea was to get something good looking quickly with this technique.
|Note: One last thing worth mentioning is that you should paint the contents of your vials before trying to paint the end caps. That way, you don't have to worry about any stray marks as they'll get cleaned up when you go to paint the end pieces.|