I’ve used this surface design technique a few times on my ceramics. It can be a fiddly process but I find that there are lots of benefits to using this technique if you overcome them.
Firstly, paper isn’t the only material that makes a good resist. Wax is another common resist used in ceramic decoration. The properties of the resist material need to be that it will shield your clay from absorbing the additional slip/ underglaze/ glaze that you wish to add to it, and that it can be removed afterwards. Removal can either be after your top layer has dried over your resist material or through picking something that will burn off in the kiln in a way that doesn’t have any negative effects. You will also want to pick a medium that can be applied to uneven surfaces, as ceramic surfaces are rarely flat.
You will first want to take your paper resist, which can be any shape that you desire cut out of paper. The benefit of this is that you can draw your design flat which is much easier than drawing directly onto a difficult form shape. This is additional beneficial to myself as I only have set occasions when I can access my ceramic studio and so it means I can do my resist preparations at home.
This is the fiddly part. You will want to take a small damp sponge and use it to press your paper resist onto your form. I had read that newsprint paper was the best paper to use, but I found it far too stiff. I use flip chart paper. This paper is absorbent enough and flexible enough to adhere to the form in a way that makes remedying inevitable creases possible. When you try to place a flat paper design on even a slightly inwards curve like a dish or bowl it will cause the design to change directions and crease. I recommend using flip chart paper, a bit of logic and a steady hand to encourage the areas where your design creases to overlap in a neat way that disguises this effect. Otherwise you end up with areas of your design that cross when you don’t want them too, or straight lines that suddenly jaunt off.
Ensure that the paper has adhered at every edge to prevent any unwanted colour seeping underneath but also think about how you might removes the paper afterwards. If your design is going to continue to the edge of your piece I recommend that you leave an additional length of paper at the end to use as a tab when it is time to remove the resist. When sponging the paper on I tend to sponge it in the direction that I know I want the creases to fold over to so that they remain within the design and won’t affect the outline of the piece once slip is added on top.
I tend to use this technique with coloured slip at the greenware stage but you could use it with underglaze and glaze too, just be aware that from bisque onwards the paper won’t adhere to the form with water. You would need to consider using a different kind of resist, such as wax, or being incredibly steady and dabbing on your colour ensuring no movement of the resists even slightly.
Colour slip usually takes a few layers to build up colour and so I recommend using a hair dryer between each one (from a distance, gentle heating) to dry between the layers. You don’t want the layers to be completely dry as the slip still needs to stick to the layer beneath, but if you add layers onto wet slip it will just move the clay about. Wait until the slip loses its sheen before adding another layer.
Once you have a sufficient amount of layers that you cannot see the clay through the slip you can peel off the resist. I will often dry this top layer a little so it doesn’t smudge but equally I don’t want the slip to be at risk as chipping off whilst I remove the paper. You can then instantaneously see how your design has come out.
If the colour does seep through, I find it easiest to wait until the slip dries and then scrape it off. If you start trying to wipe it you risk upsetting the beautiful crisp lines that this technique creates.
Flip chart paper, I’ve said it already and I’ll say it again. This technique takes practice and the more complicated the surface shape the more you’ll need control of your paper.
Once your resist is removed you can add detail with oxides and underglazes if you prefer your design not to be a flat, bold shape.
Don’t have elements that sprout from the body of your paper resist that are too close together, otherwise you risk them crossing and touching if you are placing them on a concave surface.
Practice using this technique on inward curving surfaces and outward curving surfaces so that you can learn how to compensate shaping your design depending on how it will be applied.