Masking your pieces for airbrushing multiple colours in different areas is a key technique. I generally use Tamiya masking tape because it’s not apt to pull the paint off when you remove it, and it comes in very convenient sizes. I’ll sometimes use liquid masking fluid, but only when necessary as it’s tricky and a touch messy.
What to mask? General rules:
When you’ve decided that you need to do some masking, it’s important to think of which area you mask and which order to do the paints in.
Generally, I’ll lean towards masking the smallest region, so that would mean I’ll paint the small region first, then mask it and then paint the larger region. If the smaller region is tricky to mask, I’ll mask out the larger but that doesn’t happen too often.
Masking when you’re going to be painting really contrasting colours can be hard, as ideally you’ll want to paint the lighter colour first, and then the darker which should fully obscure the underlying lighter paint. If that’s un-avoidable I’ll paint the darker colour first, but then after masking lay down some grey undercoat before painting the lighter colour. Usually the undercoat will be strong enough that you can’t see the darker colour coming through.
Some paints are strong enough that I’m happy to apply the masking tape directly to them, knowing it won’t pull the paint off when I’m done. For instance Tamiya gunmetal goes on tough and glossy and makes a great surface to put masking tape on. Similarly the Alclad primers can usually take masking tape just fine. In other cases I’ll use a thin layer of Future Finish to protect the paint surface from being removed along with the masking tape.
Using the Patlabor 1/48 Ingram kit, I’m going to demonstrate some masking techniques and also discuss how I decided which sections to mask to best achieve the end result.
I’m going to be masking on the Ingram where the instructions ask you to apply stickers.This part is moulded white, but the kit comes with black stickers that go along the edge. The black stickers have orange patches at the ends for lights. On this kit I’m using Tamiya gunmetal instead of black (as I’m not usually a fan of pure black on models) so I’ve started painting the entire piece with gunmetal. As I noted above, Tamiya gunmetal is a safe paint to add masking tape to without a top coat. Here’s the rolls of Tamiya masking tape I use – 5mm, 10mm and ??mm. I’m using the 5mm tape for this, so I cut off a length and stick it to my desk. Now I’m first trying a length along this edge, but it’s too thick to stick nicely. So I cut the strip in half with my scalpel. These thin sections work much better. I add them length by length, just roughly guessing how long a piece I’ll need and trimming if necessary. Always keep referring back to the stickers or artwork to ensure you’re masking the right part. Here I let the masking tape go over the top of the indented section. Using a sharp 2H pencil I drew around the edge I want to cut. This serves two purposes – to make the edge more easily visible, and to make the tape conform to the edge better. The scalpel is a nice sharp fresh blade so I gently cut along the edge, and use the blade to lift the cut section. This piece is now ready for grey undercoat (to hide the gunmetal) before I use the white paint to finish it. For this section I’m going to use the stickers that come with the kit as pre-shaped masks. There’s no really nicely defined edge for where the paint goes, so using the sticker should make the results accurate. The piece has been undercoated with Alclad grey undercoat, and then painted with a slightly darker grey ready for masking. Because the grey paint is not super-tough, I put a nice layer of Future Finish on top and let it dry thoroughly. After carefully adding the sticker this piece is now ready for the white paint. These sections started as white plastic, but need some sections done in gunmetal. I started by painting in where the gunmetal needs to go. Now I just cover the panel line with the tape. Because some of the line is straight and to save cutting I align the tape with that panel line edge. That leaves an indented section to cut. I use my 2H pencil to make the edge visible… ..and gently cut it out with the scalpel. The trimmed section didn’t go to waste – I used it to cover the thin sliver of gunmetal the masking tape missed. These sections are super-detailed, so I’m not sure if the masking is going to work. I may have to do some hand painted touch-ups. Because the gunmetal works well hand painted, I’ll mask it, paint the white and then come back and see if any small areas need a touch!Starting with the flat sides, small sections of masking tape that fold over the edge. If any tape goes too far, use the pencil to push into the corner and trim with the scalpel. I add a band over this section. Then press in with the pencil, cut down the sides and remove, then same again on the next section up. There’s no wrong way to do this. Just keep adding tape and trying again if it doesn’t work. Use the tip of the pencil to gently push the masking tape into place around the details and to help it stick firmly.Here’s all four pieces now ready for grey undercoat (to hide the gunmetal) and then white paint.
When the grey undercoat was dry, I then used the white paint on the pieces. I went gentle with the white paint because you don’t want the piece so wet as for the paint to seep under the masked edges, and you don’t want to spray so hard that you move some of the masking tape!
Once dry, it’s time to remove the tape and see what you got. Don’t worry if there’s very small imperfections as you can easily touch them up with a fine brush and a drop of paint. If you need to do more than that, strip the piece and try again.Here’s the piece with the masking tape removed. It came out pretty neat, which is usually the case for straight edges. I touched up the very fine edge here because the white paint had blown under the masked edge. Not to worry as it was so small a touch-up as to be unnoticeable. It’s hard to see the edge, but the line between the gunmetal and the white is very clean. The original sticker had orange sections for the lights, but we’ll tackle that later…. Removing the stickers we see the dark grey paint looks great against the white edges. These small sections came out great. And I was surprised how well these tricky pieces worked.
It’s important to note that I removed the masking tape before top coating all these pieces. You want the top coat to go smoothly over all the paint, and not make an artificial edge along the masking tape.
Masking is also useful for when you’re doing seam-line removal. The legs come in two halves, and the knee section joins in with a flexible plastic sheaf around it, meaning it must be inserted as built and not later. The knee cover section has a small dark section that I masked before inserting it in, but the piece is round and the masking tape should just pull off when done. The flexible plastic has a lot of masking tape all over it. I used the pencil to push the tape between the plastic sheaf and the leg armour pieces. I also bent the knee to allow more masking tape behind the joint to ensure all the plastic sheaf got safely covered. I then glued the halves of the leg together with thin liquid cement, and used a sanding stick to smooth out the seam line. Here the pieces all have a couple of good coats of Alclad grey primer on them. Once that’s thoroughly dry over night, I’ll sand again then prime to see how the seam looks. Hopefully it will be good and ready to paint. If not, I’ll just repeat the process of sanding and priming until it is! After a few iterations of sanding / priming, the seam lines are gone.Removing the masking tape, the piece is now ready for panel lining.And the head now has no ugly seam along the top, and is also ready for panel lining.
Don’t mask unless you have to!
Remember I mentioned the orange part of the sticker on this piece? I’ve cut some very thin strips of metallic tape and are placing them where the lights go. There’s small indents in the plastic to mark them, which makes life easier. Once they’re in place I can carefully hand paint some clear orange over them to make lights.So just because masking is a cool and useful technique, it doesn’t you always have to use it when you need colour differentiation on areas of a part.