I think many beginning potters start out with the goal of making perfect sets of bowls or mugs, but quickly realize that it isn’t that easy to make exact duplicates on the pottery wheel. It can be argued that this is precisely the charm of hand-made objects–that they are not perfect. If you want perfect, you can get factory-made pottery at your local big box store.
But, if you still can’t let go of the idea of making exact sets, you might want to try using a throwing template. Today, potter Bill Schran explains how he makes and uses templates to throw multiples on the pottery wheel. Enjoy! – Jennifer Poellot Harnetty, editor.
When my beginning wheel-throwing pottery students have developed a sufficient facility with clay, they’re assigned the project of creating a set of four matching cups. Though I’ve demonstrated to students how to measure their forms using calipers and other devices, I continue to observe them experiencing difficulties. In an effort to overcome this stumbling block, I decided to show a technique that has been successfully used by students in my beginning handbuilding class.
This technique involves the use of templates (or throwing ribs) to repeatedly create an even, symmetrical form. In the coil-building exercise, the template is positioned abutting the pot as coils are added, making certain the pot conforms to the profile of the template. The template is then used as a rib to scrape the surface of the pot as it is rotated, creating a smooth, uniform surface.
Making a Throwing Template
To incorporate this technique into wheel throwing, I began with testing of various materials that might serve the function of a template. The result of these tests proved to be sheet plastic, a durable material that can easily be cut and shaped. Searching through scraps available at local glass supply and repair shops, I found pieces of 1/4 in. and 3/16 in. sheets that could be cut with a power saw and handsaw and could be readily shaped into the desired profiles. The edges can then be smoothed with fine sandpaper. This process can also be used to produce templates with more complicated and compound profiles with relative ease. The image to the right shows an assortment of throwing templates made of sheet plastic.
Creating the Form
To use a template, as in the wheel-throwing project for the set of cups, prepare several balls of clay weighing between ¾–1 lb. each. Throw a basic wide cylinder. Check the interior diameter, height and width of this basic form with calipers.
Tip: Make a template for the basic cylinder form as well as the finished piece. The first template, showing the right width and shape of the ideal starting cylinder, can help you get the right basic shape.
Once you have your cylinder ready, lubricate the interior of the pot, but do not lubricate the outside. Avoiding excess water results in a stronger form that can better withstand manipulation and alteration when using the template.
Position the bottom of the template so that it’s just touching the bottom of the pot and rests on the wheel head. The template should contact the wheel but should not be pressed against it. Hold the template at approximately a 45° angle, abutting the rotating clay, such that the clay moves away from the edge of the template. The template should not be held at a 90° angle to the pot as this may lead to inadvertently shifting the template into the movement of the clay.
The fingers of the interior hand slowly move up, pushing the clay out to the curve of the template. As the pot widens, the hand must move up along the interior of the form more slowly so that it remains symmetrical. After reaching the top, the profile of the pot and template should be compared. If the pot does not match the template, move the fingers of the interior hand down from the top to the bottom, pushing out where necessary, to conform to the profile of the template. This is often necessary for shapes with wider diameters. Refine the rim with a sponge or chamois and the cup is complete.
Large or Complex Forms
Templates are also useful in creating larger pots, particularly bottle shapes. The profile template provides a method to quickly create multiples of the same form, but also the opportunity to explore changes to certain areas, such as the neck and rim. The process of working with larger forms follows the same steps as you would for cups, except the neck and rim are made without the template, after the basic shape has been defined.
To get started, make another cylindrical shaped pot, leaving the top portions of the wall, including the rim, thicker than the rest of the pot. Position the template and push the clay out to conform to the shape, moving fingers on the interior up and down as necessary. After creating the desired curve, pull up the upper portion of the wall to thin it out and narrow it in using a collaring movement. Note: It is very important to continue moving your hands up while collaring in to maintain a curve or arch in the shape of the wall. A wall that becomes too horizontal or flat during the collaring and thinning process may be pulled down by gravity and collapse. In order to collar in the pot, use the middle fingers and thumbs to constrict the neck. As you create the neck, pressing down on the rim with the first finger of the right hand helps to maintain a level top.
Use a flexible rib after each collaring process to refine the shape and maintain the desired curve. Using the rib also removes excess water and compresses the clay. After narrowing the diameter of the pot, the wall has been thickened and can now be pulled up thinner. As the top becomes too narrow to insert a sponge to remove lubricating water from the interior, switch to using slurry to lubricate the clay instead. This allows your fingers and tools to continue shaping the clay without building up excess torque that might twist or tear the clay wall. Using slurry on the exterior, instead of water, provides a stronger clay wall.