How do undercoats effect the final color? (painting)

[KyozoKicks]

Hey guys, first thread and first question from me!

I have been wondering if anyone has any advice or any good resources where I can read up on how the color of an undercoat effects the final color you apply. Whilst I have a vague idea of simple methods I recently read about people here advising a glossy black coat under a layer of gold to achieve a visually pleasing finished model. Would like to learn a bit more on this.

Thanks in advance.

 

[Prefect42]

Greg Jein once told me that to get a good, bright yellow or red finish, spray a silver undercoat. I've tried red over grey primer and it's dull and flat. With silver underneath, it really makes the red and / or yellow pop. So use primer / silver / RED or YELLOW.

You might want to take a scrap piece of wood / plastic and do a few tests. Use a black sharpie pen to note the undercoat and top coat. With a bit of blue painters tape, you can have a handy reference for yourself. I did this with various types of black and it helps me decide on gloss / satin / flat for various props.

I've also used the black undercoat / gold top coat and it works nicely. Worked wonders on my Indiana Jones Fertility Idol. Learned this tip here on the RPF.

Anyone else?

Ted.

 

[JMChladek]

I would encourage testing as well. Gloss black basecoats are one of the in things these days to use with metallics to get them to pop, although theoretically with the Alclad paints, it isn't as critical unless you really want a bright chrome look (which might look great on the Pegasus "When Worlds Collide" space ark). One thing I do know is white is ALWAYS one of the hardest colors to paint over a basecoat that is darker then a light gray shade and if there are any dark spots, you will likely still see them after painting unless you can do spot applications with an airbrush. Yellow is almost as bad. Orange and red shades tend to be a bit better in that regard since the pigments aren't as transparent.

Pre-shading is a big thing among some modelers these days as putting weathering stripes down on a model, then going over the top with the color coat can yield a more multi-tonal paint look where the paint goes over the dark streaks. One thing you may need to be careful of though is it may alter your paint shade to one you don't want. When I did my last Millennium Falcon model, I tried doing a shade of Testors MM Light gray over an all black base coat. The result was a paint shade that was bluer then I wanted as the black coat shifted it that direction. My solution was to mix a 50/50 shade of camouflage gray and light gray so that the warm nature of the camo gray would negate the effects of the black basecoat to shift it bluer. It achieved the result I was after when I was finished.

As Prefect42 already mentioned, one thing that can be done very easily is to get some scrap plastic or styrene sheet and make some color chip tests. Try spraying each with a different base coat and then mark off and go over the top of each with certain colors you want to try. When done. you should have a clearer idea of how each color interacts with that base shade. I also have done the color chip test of JUST the black shades and you would be very surprised to see how many blacks are out there. Some are bluer then others, some have green shades. All are black though and you don't really get to see how different they are until they are next to one another.

 

[Rhett J Martin]

My basic rule of thumb has always been;
light color=white primer
dark colors =grey, blacks
dark, dark colors or black =black primer

. . .but most of my kits in teh past haven't strayed far from the typical military/sci-fi pallate (sp?).


BUT I've NEVER heard of undercoating with silver!! What a genius idea. I've got a fire truck model just aching to have that tried out on!

 

[KyozoKicks]

Some great advice/tips guys. So would you only really undercoat with various shades of white, greys and blacks?

 

[Gigatron]

For colors like red, orange and yellow, undercoating with gloss white, also makes the color pop.

Depending on the heaviness of the top color, the undercoat may end affecting the final shade of that top color. A lot of model builders will pre-shade recessed areas with black (over grey primer) to add a layer of depth to the top coat.

I tend to prime with grey as it's fairly neutral and predictable. It doesn't overly brighten, or darken, the final color.

-Fred

 

[rustysprattdesigns]

When I had my Chevy s-10 painted we used a house of Kolor Shimrin Silver, it's a pure metallic base,( if I had enough, I was very tempted to leave it with the silver, anyway,) followed by Kandy Organic Green for the top coat. We could have went with a darker base, but it would also make the top coat darker, and like Gigatron said, I really wanted it to pop!

Basically darker under coats will make your base a shade or two darker, and lighter colors will do the opposite. This has been my experience with it, hope it helps.

 

[Wes R]

i primer everything with gray or red (i love the walmart cheap primers, they're nicer than the real paints) and i have true value yellow primer which works amazingly well as paint.

 

[JMChladek]

The silver under red or yellow isn't much different from paint work done in the 1970s and 80s on custom cars with candy paints. They were designed to go over a silver basecoat and required multiple passes to build up the color. But when done, the result was a nice, rich eye-popping color that wasn't exactly a metallic, but made the best use of metallic properties to enrichen the colors.

You don't have to use just black, white and gray shades to get paint effects. Pick up a book on basic color theory and you can find some other things to try as well to make certain colors pop. For instance, in pre-shading, the use of Earthy colors such as raw umber instead of black or gray shades can add to a certain weathering look as well. Experience with different colors can really improve your paint arsenal on models.

 

[KyozoKicks]

As expected guys some great advice. Going to put some of it into practice tomorrow.

I'm going to be painting the walls that appear in Andys bedroom in Toy Story (The sky and clouds) on a canvas material. The canvas it pure white where as the blue to go on top of it is quiet subdued so I think I will go with a light/medium grey and than the blue on top of that. Although I am interested to see how the silver would look so with a scrap piece I think I'll have a practice run :unsure

Anymore advice please share, a topic I'm likely to revisit time and again - interesting stuff already posted :thumbsup

 

[SingleSeat]

Test, Test, Test!

 

[ae35unit]

Hey guys, first thread and first question from me!

I have been wondering if anyone has any advice or any good resources where I can read up on how the color of an undercoat effects the final color you apply. Whilst I have a vague idea of simple methods I recently read about people here advising a glossy black coat under a layer of gold to achieve a visually pleasing finished model. Would like to learn a bit more on this.

Thanks in advance.

I found this interesting post on the web where gloss red is recommended.

Something you might [or may have already] try...
I used to do gold leaf work and gold paint work.[which you probably know, but most don't, is made up of bronze dust among other metals]

I learned from Italian craftsman brought over to do an old theater renovation. We used a dark but bright colored burgandy on some work or a dark fire engine red [for lack of a better description] as under coat. Both very high gloss. Then the gold leaf or paint, paint several light coats, and finally 2-3 clears.
This was done on highlights on plaster crown, mirrors, door trim, furniture, etc. When asked about the red undercoat vs other colors, the simple reply was...
This is the way it has been done for centuries and it is the best!
Also did exterior work on High Victorian houses, bracket detail on cornice etc, the same way but followed by clears with uv protection rather than varnish [interior work].
I have done a couple of rockets with silver, never done gold [yet] with very good results. You might want to on test on paper.
The picture does not do the finish justice, but you can see the sun glaring off the finish its blinding. This was Rustoleum indoor/outdoor silver metallic.

 

[newmagrathea]

I asked this same question on a thread about reds and I was told to use a yellow undercoat to make the red pop, or a dark color like grey or black to make them darker/duller. It all depends on the effect you're trying to get. Also keep in mind if you are going to do any washes over the top, that will change the appearance of the color as well.

 

[madmikeee]

The base color or primer will affect your final topcoat. Rule of thumb in body work is to tint the primer according to your topcoat. IE gray primer, tint with red will give you a richer red topcoat. Lighten the primer to a whiter one and you will have a BRIGHTER red. One thing though, at least in the automotive paint world, you MUST be sure that your chemicals are compatible. One miscalculation and you will have a contaminated paint job which will require stripping it back to bare metal. They make tints specifically for primers. For small jobs, as said above, silver is a great base to make colors pop. For large jobs though do a little research on your chemicals just to save yourself MANY hours of annoyance.

 

[Clerval]

Not sure where some of the above is coming from esp as you'll be working on canvas (though you mention that later). If you need to finish the canvas to prep it for paint, keep it white. Depending on the nature of the paint/ground, these days you can paint with complete impunity, with close to no regard for what sits over what. However, you want to hedge your bets and allow layers, if you must work in them, to work together, and so if you find you need to, then some of the above will help. But you're trying to color match, not create a mood or evoke anything in an illustration, and not creating or mimicking a surface on a scale model.

If you don't have the experience yet, don't rely on influences of one layer on another. Paint directly what you want. In your first tests, keep the color purer, be slow to take down the saturation and value and let the paint sit a bit (in case these shift while drying) before making any decisions. Have a scrap piece of canvas treated the exact same way to paint and notate your tests on. If you need to lighten your base color, note that most whites also have their own bias (as do blacks), and you may inadvertently shift the blue even cooler than you realize depending on that... if you must lighten, try to do so with a blue which has the properties you're looking for.

btw, anyone know if this ever had a follow-up or if images were posted?

 

[kruleworld]

My basic rule of thumb has always been;
light color=white primer
dark colors =grey, blacks
dark, dark colors or black =black primer

that's pretty straight-forward and my standard too. I also do red tones (orange to purple) with red undercoat (aka red oxide primer) and grey for blues.