CJ,
I used to use leather dye for both wood cars and wood structures. It works great for either because the surface is porous and you can control how much weathering you get by just sticking the the brush first in the dye and then swirling it around in a small bowl of solvent. I never used alcohol but I'll take your word for it that it works.
Jeffrey, maybe that's the issue. With india ink, you just dip you brush in the bottle and then dilute it by applying it full strength to the model and them using a clean brush with alcohol to thin it down on the model. You can also have the alcohol in a small bowl and dilute it the way I described using leather dye. You wouldn't want to make up a whole quart of the stuff already diluted because then you have no control over how the model will look. I have a one ounce bottle of Dr. Ph. Martins "Black Stain" india ink I got at Hobby Lobby for $6.69. You can also get it at Michael's. As you know, I have a lot of structures and a fair amount of rolling stock and almost all of was weathers with some amount of india ink. I've uses about 20% of the bottle in a year.
CJ also had a good point about dullcoting the model first. This gives the plastic some tooth so the india ink doesn't just run down the sides and make big blobs on the surface. I almost always follow up with some weathering chalks and then dullcote the model again to protect the finish from handling.
I used to use leather dye for both wood cars and wood structures. It works great for either because the surface is porous and you can control how much weathering you get by just sticking the the brush first in the dye and then swirling it around in a small bowl of solvent. I never used alcohol but I'll take your word for it that it works.
Jeffrey, maybe that's the issue. With india ink, you just dip you brush in the bottle and then dilute it by applying it full strength to the model and them using a clean brush with alcohol to thin it down on the model. You can also have the alcohol in a small bowl and dilute it the way I described using leather dye. You wouldn't want to make up a whole quart of the stuff already diluted because then you have no control over how the model will look. I have a one ounce bottle of Dr. Ph. Martins "Black Stain" india ink I got at Hobby Lobby for $6.69. You can also get it at Michael's. As you know, I have a lot of structures and a fair amount of rolling stock and almost all of was weathers with some amount of india ink. I've uses about 20% of the bottle in a year.
CJ also had a good point about dullcoting the model first. This gives the plastic some tooth so the india ink doesn't just run down the sides and make big blobs on the surface. I almost always follow up with some weathering chalks and then dullcote the model again to protect the finish from handling.