Any way to mimic oil pastel texture?

[Nookkemstudio]

I want to try to develop a recipe to make an underglaze pencil that has the texture of oil pastels. I like the smoothness of application and the texture that oil pastels have and was wondering if there's any existing recipe or product that mimics this? Any tips?

Thanks in advance!

[Nookkemstudio]

I saw a ceramist mix englobe and mix it with wax (she didn't fire it) on instagram. Does anyone have experience doing something similar?

[Callie Beller Diesel]

While they’re gaining more widespread use, the majority of commercial underglaze users are students or folks in some kind of setting where immediate results are needed to encourage people to keep at it. So the commercial ones are all water based products, because it makes a bunch of processes easier to streamline. It’s assumed in most of these settings that underglazes have a glaze applied on top of them, although if you’re making non-functional work, it’s really not necessary to do that. 

That said, others do make their own home brew underglazes to save a few dollars. While all the recipes I’m aware of are also water based, it seems reasonable to my mind that you could take the same mason stain/flux/clay recipe, and mix it with an oil/wax combo that gives you your preferred pastel consistency. Artist’s pastels are, after all, basically this. Pigment, filler and vehicle. You’d have to bisque any pieces thoroughly before it’d be able to take any glaze covering, if that was your intent. 

When I was making underglazes, I was using a simple mix of equal parts epk, mason stain, and a frit that was also an ingredient in the clear glaze I’d be putting it over top. Don’t use any flux or glaze with zinc, if you want to keep the stain colours true.

 

[Callie Beller Diesel]

Although it occurs that if you’re making sculptural pieces, yes, you could just use encaustic (wax and oil). You don’t need to glaze fire a sculpture unless that process will give you the surface you’re after.

[Nookkemstudio]

Thanks Callie! Ill definitely test out mixing oil/wax with my regular underglaze pencil recipe! I definitely have some experimenting to do.

Do you know if I can use any oil for recipe development or if there are any oils I should avoid putting in the kiln? I want to make functional works (cups, plates, etc) so I plan apply the "oil pastel" on bisque fired work and than put clear glaze on top of it. I'm worried that the clear glaze will melt my intended effect/texture of the "pastels" but I guess I have to test it out to see!

[Callie Beller Diesel]

As far as combustibles, pretty much everything organic burns out at bisque temperatures. You’ll have to be more concerned with your kiln ventilation. I have to reiterate that you WILL have to bisque, decorate, rebisque and glaze fire if you want to try and glaze over something like this. If this is being done in a kiln you own, be aware of being around whatever you’re burning off. If you are in a teaching or shared studio environment, you’ll need to consult with the powers that be to see if they’re willing to let you do this. Some studios are more structured than others. 

If you’re going to glaze over these pieces, unless the glaze is a really runny fluid one, it shouldn’t erase any scumble texture. As long as you have enough clay in your mixture, it should remain fairly refractory, and not want to move. 

I don’t know if it’s the process or the end result that’s more important to you. If it’s a specific look you’re after, it might be a lot easier to achieve by dry brushing coloured slips instead of making your own oil pastels. If it’s the process that’s more interesting to you, have at it with the oil pastel idea. 

[Magnolia Mud Research]

1. an oil or wax pigment will repel a water based glaze applied over the marks you make.  
2. I have used various brands of art "pastel sticks", water color paints on green ware and over glazes before the final firing.  The outcomes depends on both the pigments, the glaze, and the amounts applied of both.  Some works fine, others not so fine, and a few combinations made a mess.   
3. Many of the "art" pigments are non-metallic (aka organic compounds), and the pigment actually "burns" in the kiln; some leave a mark, others do not. I tried both on clay based items with glazes and on fused glass work.  some burn way, others leave marks and/or color.  testing is only way to find out. 
4. When I was doing the testing (~15 years ago) there were some commercial "ceramics pastel" sticks that worked well.  I think the brand was AMACO; have no idea if they are still being supplied.  There is a section in one of the Robin Hopper books that discussed making the "pastel sticks" ("Ceramics Spectrum" comes to mind). The "sticks" worked just fine when I tested them.  

I recommend:  Try it, it might work! 

LT

[Min]

Just adding a bit to what @Magnolia Mud Research said, the Amaco underglaze chalks are still available, link here with a little video showing them being used in a different way over glaze and gum.  I found them a bit fragile and they did crumble a bit with age. This link might be a snippit of what is being referenced from Robin Hopper. I'ld do a search here for Cuerda seca as well, linseed oil is sometimes used but I'm sure other oils have been used also.

[Babs]

You write of texture.

Would the "texture" just fire out?

Are you looking for real texture?

Stains etc mixedcwith a thickened slip??

Texture would remain.

CMC would make it oil painterly, just trying to clarify your use of word "texture".

[Nookkemstudio]

Thanks everyone! Looks like I have some experimenting to do! Thanks for all the ideas!

@Callie Beller Diesel I make my work at a community studio so I definitely have to ask about using different materials in the kiln. I'm interested more in the process because of how smoothly oil pastels go on paper. I like how the pastels can be layered on top of each other and the ease of blending. But I definitely find a different method to do this! I guess I shouldn't be too fixated on the "oil" part of it.

Thanks @Magnolia Mud Research I forgot about how oil/was repels glaze, I definitely have to keep that in mind! I've played around with the Amaco underglaze pencils a long time ago, maybe I'll look into those as well.

Thanks @Min for the link. The second link is very helpful, it looks like Robin Hopper says to mix wax resist to make a crayon. I might try to play around with that idea and just not glaze the final piece.

@Babs I like the texture of oil pastels when they're applied thick on top of each other, they leave a bit of a protrusion because of all the layers stacked on top of each other. I also like how I can use it to get a crayon-like texture when I want to apply it lightly. I like the stains with thicken slip idea! Maybe I can play around with that and use my underglaze pencils on top to give the layered effect, thanks for the idea! I never used CMC before, I'll definitely look into it. If it gives a painterly effect, maybe that's what I'm looking for.

[Min]

1 hour ago, Nookkemstudio said:

I make my work at a community studio so I definitely have to ask about using different materials in the kiln.

This might be the biggest stumbling block. Most community studios have policies in place where only materials bought or supplied through the studio can be fired in their kilns. Last thing they want is someones work damaging their kiln / shelves / others work.