I am trying to create a rather strong terracotta and just cant manage to get my reds to stay strong. I have six of them, iron oxides, burnt siennas and two other mixed earth colors, and when I add them to the vp, they all turn either pinkish or (sorry) vomit-color. Adding black just muddies them, and adding yellow helps a little but not much. Please help! Thanks

Welcome to my world! Reds can be very difficult but not impossible.
Try this first...
Ir.Ox. Red, Warm Hue, enough Mars Yellow till it starts twords Orange, then Ir.Ox. Black to tone it to Terracotta.
If that does'nt do it for ya, then try this one... but watch out...
If you're still having a difficult time with Ir.Ox. Red, Warm Hue, try starting with Irgazine Red or even Irgazine Ruby, work in some Ultramarine Blue, yes it will start to look purplish, but then add a touch of Iron Oxide Black. The black will bring it back "down" but be careful - Ir.Ox. Black is very potent. Too much of it and you will be starting over. If you overdose on black, there is no turning back. Remember when we were kids... "Touch black - no backs." Boy, I may have just aged myself with that one, but it's certianly true with color mixing! at this point you may need to add Yellow to mellow out the "blood" color you just made. You will need to "play" with it until you reach a formula you like because all of the materials and applications techniques differ and some materials just won't accept color that well anyway.
Some Venetian plaster suppliers offer their own tints and you may want to go that route if it's available to you.

THanks so much for the reply. Well, here's the added difficulty. I want to stick to non-manufactured pigments, so the question becomes, can you think of a way to get to the nice terracotta using the ochres and natural reds, etc.?

>THanks so much for the reply. Well, here's the
>added difficulty. I want to stick to
>non-manufactured pigments, so the question
>becomes, can you think of a way to get to the
>nice terracotta using the ochres and natural
>reds, etc.?

Those are the only ones that you can use (ochres, red oxides, mars, etc...)

what do you mean non-manufactured?

You need ONLY (lime in the plaster will "eat" (destroy) any synthetic or organic pigments) natural earth/minerals and those Mitch are refers to and those are the only ones to use... You dont have to grind rocks yourself...
unless you find a clean and pure deposit of a certain mineral, then you better put a factory there

>>THanks so much for the reply. Well, here's the
>>added difficulty. I want to stick to
>>non-manufactured pigments, so the question
>>becomes, can you think of a way to get to the
>>nice terracotta using the ochres and natural
>>reds, etc.?
>
>Those are the only ones that you can use
>(ochres, red oxides, mars, etc...)
>
>what do you mean non-manufactured?
>
>You need ONLY (lime in the plaster will "eat"
>(destroy) any synthetic or organic pigments)
>natural earth/minerals and those Mitch are
>refers to and those are the only ones to use...
>You dont have to grind rocks yourself...
>unless you find a clean and pure deposit of a
>certain mineral, then you better put a factory
>there

Thanks again so much for the reply. Sorry, my mistake on the pigments. What I meant was that I wanted to use only the ochres & natural earth pigments, so the mars reds and yellows are out. I think I may have given up on achieving the depth I want with just VP, though, and am now thinking about using a glaze over the vp. I tried a traditional turpentine/linseed oil glaze but it of course sank right into the vp - BUT this may be bc I didnt let it cure; i.e. I applied the oil wet, and the VP drank it up like someone in the desert. I am thinking about how I could EITHER use two coats of VP; i.e. yellow undercoat, red on top, and then sand back the first, OR a yellow ochre coat of VP with a red glaze. Any comments on any of this? Oh, as a final touch, I saw in Kevin McCloud's book a nice top coat of a white wash meant to simulate the "saltiness" that terracotta gets. I would be thrilled to able to achieve the yellow/red/white undulation. I think it would be georgeous, and I know there's a way to do it, but I'm unsure about the mixed media. Thanks...Maria

>
>Thanks again so much for the reply. Sorry, my
>mistake on the pigments. What I meant was that I
>wanted to use only the ochres & natural earth
>pigments, so the mars reds and yellows are out.
>I think I may have given up on achieving the
>depth I want with just VP, though, and am now
>thinking about using a glaze over the vp. I
>tried a traditional turpentine/linseed oil glaze
>but it of course sank right into the vp - BUT
>this may be bc I didnt let it cure; i.e. I
>applied the oil wet, and the VP drank it up like
>someone in the desert. I am thinking about how I
>could EITHER use two coats of VP; i.e. yellow
>undercoat, red on top, and then sand back the
>first, OR a yellow ochre coat of VP with a red
>glaze. Any comments on any of this? Oh, as a
>final touch, I saw in Kevin McCloud's book a
>nice top coat of a white wash meant to simulate
>the "saltiness" that terracotta gets. I would be
>thrilled to able to achieve the yellow/red/white
>undulation. I think it would be georgeous, and I
>know there's a way to do it, but I'm unsure
>about the mixed media. Thanks...Maria

Oh, I see - this is much more clear than the other thread. Mars is just another name for iron oxide, but if you want to stay away from oxides, that is fine.

Do what you have outlined sanding also - will give nice effect. make sure you let it dry between coats completely. then before applying the glaze - seal it with any plaster sealer to stop from absorbing the glaze.

Then glaze avay like you would glaze a regular wall.
The only "problem" (traditionally true marmorinos were waxed and polished) I can see is that you will not have matte surface, but you can apply matte top-coat or deglosser afterwards.