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Dear friends 

following a disastrous attempt at painting the waterline I decided to take a step back and do a bit of testing. My main problem was bleeding of the paint under the masking tape.

It seems that the consensus is that Tamiya masking tape works and it was also suggested to me to use masking film which seems a great but expensive option.

However I first thought of testing tapes that are cheap and widely available, a general purpose masking tape by 3M, insulating (electician's) tape and frog tape (low tack).

I intend to test these tapes on common modelling substrates, that is sealed and sanded wood, primed wood and cured paint. I will also use red auto paint (Halfords) and modelling acrylic white paint (Humbrol), both spray cans.

It might be useful to post a few photos with the results.


I prepared three pieces of plywood, (sanded to 400 grit, then acrylic sanding sealer, followed by sanding to 400 grit)




First test is the sealed wood surface.

I applied the three tapes, white is insulating, blue is masking  and yellow frog. I painted one half with the red auto paint and the other with the white acrylic (2 coats each).








The red paint was applied first and the two halves were separated with the 3M blue masking tape well tucked down. Although unintentional it is evident that a lot of white paint has bled and the line is not sharp.




In the next photo the blue masking tape was top and the frog tape bottom. The masking tape bled a lot with both paints but the frog tape was almost flawless. 




In the next photo the insulating tape is top and the masking tape bottom. The insulating tape was better but still there was some bleed with both paints. Also, the tape left glue residue on the wood.




On sealed wood the yellow low tuck frog tape is the clear winner and the only real option, allowing crisp lines for a cost of £6 for 41 m (24mm). The dead cheap insulating tape if extra care is used may have reasonable results but is far from perfect. The ordinary masking tape simply should not be used for masking purposes.

Of note, the Humbrol paint left a raised edge when the tapes were removed but not the Halfords one.


Next comes the same on primed and painted surfaces.

Edited by vaddoc
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I use Tamiya tape for almost all painting jobs where a clean line is required. The only drawback is that the narrowest Tamiya is 5mm wide.  Sometimes you need something narrower.  For this you could try Pactra which is also excellent.


Bob (RMC)

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You may want to lay your making tapes on a clean metal or glass surface and cut it with your sharp knife and a metal straight edge. The flat surface with take some of the tackiness off your tape and the fresh cut tape edge is way crisper than the factory cut edge. And like grsjax said, seal the edge.

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One problem with Frog tape (and perhaps with others like it) is that when it is cut to a certain pattern the edge is removed and the benefit of its properties is also gone.

When you read how Frog tape works you find out that the edge of the tape is treated with a special chemical. Once that edge is removed, you are back to regular masking tape.

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Thank you all for your suggestions. It seems that Tamiya tape is the most popular choice.

The purpose of this exercise is to see the effectiveness of low tech widely available (and cheap) solutions.

Grsjax, this should really work well, I however have never used or seen clear paint. 

It seems that extra care should be taken with the frog tape, it should be kept in the plastic case it comes with to make sure the edge does not get dirty and worn. I will try cutting patterns to see if the sealing properties are maintained.

Tamiya and frog tape look identical, could they be the same product?

More testing to follow when time permits

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When trying to make sure that paint does not seep under the edge of the tape a good start is the Tamiya tape or 3M Fine Line tape used in auto body painting and by many custom painters of motorcycles and helmets.  It is important to burnish the edge of the tape down onto the surface.  The 3M tape and the Tamiya will change the color of the tape slightly due to the close contact with the underlying surface when the burnishing is adequate.


A further method of avoiding paint seeping under the tape is to hit the edge of the tape with a light spray of the underlying color (the paint onto which the new color would seep) at the edge of the tape.  This assures that if any paint were to seep under the edge that it is the same paint color and is not seen. 


Another tip is to avoid spraying with the new color directly at the edge of the masking tape.  This can force paint under the tape if there is the slightest imperfection in the burnishing of the tape and it will also help to avoid a built up ridge of paint at the edge of the tape.


Tamiya and Frog tape are not the same thing - Frog tape is much thicker.  I had high hopes for it but I do not use it in my shop anymore after my testing showed it is very good for household painting but not models.


I pass these tips along to all the workshops I do on airbrushing, they will help your painting.



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I have never used parafilm but it is pretty similar to friskit that I have used - which doesn't bleed - but if possible treat it like tape and take all the precautions, being sure it is down tight, edge sprayed with base color, etc.

Another tip - always pull tape off by pulling it back over itself - never straight up, a sure way to lift the underlying paint.


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I don't always spray the base color against the tape as I have a lot of practice using the Tamiya and 3M tapes and usually know that they are very well sealed against any bleeding but when it is critical and not easily repaired or I have the slightest doubt about the seal I go to the base color spray.  It doesn't hurt to do it all the time and if you don't airbrush/mask a lot then it is good insurance.  As long as the spray is light there will not be a buildup on the tapes edge which can be harder to fix that some bleed at times.

Practice, practice, practice.


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  • 2 weeks later...

Thank you all for your comments.

I finally found some time to complete this test. I got some Tamiya tape which seems to be identical to frog tape but as Kurt said Tamiya tape is thinner so much better for modelling purposes.


I used the plywood sheet from the previous trials to see how the tapes behave on painted surface. I also prepared a new plywood sheet that was primed and sanded to 400 grit. 

I did not include the ordinary masking tape as it has already proved terrible. I used this time Humbrol enamel applied with brush


Painted surface first




The Tamiya tape left an excellent line (upper edge of white)




but the electrician's tape bled (lower edge of white)




Next the painted surface where I also used the frog tape.




Same results really, Both Tamiya tapes were good with the wide frog tape showing some bleeding where it was not tucked down firmly




And the electric tape bled




Of note, the consistency of colour is much better when applied on primed vs just sealed wood




Bottom line: Never use ordinary masking tape or insulating tape, Tamiya tape is the way forward, try and prime your surfaces.

Masking film might be another good option.







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  • 3 weeks later...

That was certainly helpful Paul.

I managed to finish painting the hull of my model using Tamiya tape and a combination of Humbrol acrylic spray and enamels hand brushed (brilliant results with enamels). My conclusions:


1. Do not use car paint sprays, they smell too much and create very (very!) thick coats

2. Tuck the tape down well. Then do it again 3-4 times and go over that little area you think does not matter. It does and leads to a sloppy mess. Cutting off a new edge with a ruler and blade as you suggest might be needed

3. Tamiya tape is brilliant, but still creates an edge that will probably need to be sanded as you said in your video to mate the surfaces. (600 grit?)

4. A flexible tape is sometimes necessary and Tamiya is not flexible. In your video you show a very flexible one, could you mention the brand?




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  • 2 weeks later...

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