|This article is about an older version of DF.|
The ceramic industry is one of the major crafting industries, using clay, kaolinite, and fuel at a kiln to form fairly expensive ceramic goods with the pottery and glazing skills. It is one of three industries that necessitates fuel, the others being the glass industry (to which it is very similar) and the metal industry. Although it has a fairly limited variety of goods when compared to masonry or similar trades, ceramic goods are naturally worth three to ten times those of common stone or wood, making it a lucrative option for building wealth. The goods that can be produced are jugs, large pots, bricks (clay blocks), statues, crafts, and beehives, made out of three types of ceramics: earthenware, stoneware, and porcelain.
The most important raw material for ceramics is clay, which is a type of soil that appears in layers. Finding out whether or not you have clay is easy: unlike the base material for the glass industry, sand, clay is reported as either "clay" or "shallow clay" in the embark screen, and if you want to establish a ceramic industry you should have clay available. What type of clay you have available cannot be determined ahead of time.
Garden variety clay, clay loam, sandy clay, and silty clay are used to produce earthenware, the most common ceramic material, with a value multiplier of three, which is more than any wood and any non-ore stone other than obsidian. The chief disadvantage of earthenware is that it must be glazed in order to store liquids, a process that is described below.
Fire clay, which has a value multiplier of four, is used to make stoneware, does not need glaze to store liquids, and is more valuable despite not being more difficult to produce. If you have fire clay, it is a free 33% value boost to your ceramic industry.
As long as you have even a single square of clay, you will be able to create as many ceramic goods as your fuel sources allow; any clay square will generate clay when worked, although clay will only be collected from squares designated with a clay collection activity zone.
The only non-clay source of ceramics is also the most valuable - kaolinite, which produces porcelain. This is a dark red stone found in sedimentary layers that must be mined out, making it a finite resource, unlike the other two types of ceramics (and very similar to crystal glass). This is balanced by the fact that porcelain goods have a value multiplier of ten, on par with mid-range ores like silver; since it is no more difficult to produce (just requiring some mining) and also does not require glazing, having kaolinite on the map is a boon for any fortress.
Before you can create any ceramic goods you must first collect some clay. To do so, you must designate a clay collection activity zone () with at least one valid clay tile somewhere in it (although having only one will cause supply issues). Dwarves with the item hauling labor enabled will either take it to an appropriate stone stockpile, or leave it there for the potter to retrieve. Because you will constantly need more clay, it is a good idea to build and put a kiln on repeat collection orders, preferably with nine redundant iterations to prevent the manager from tasking anything else there. Unlike sand for the glass industry, collecting clay does not require any sort of container.
Raw clay boulders can also be used in construction.
Once you have the clay (or kaolinite) collected and the fuel ready (if needed), you can designate stuff at the kiln to be fired by a potter. A standard kiln will consume one unit of fuel per job; a magma kiln uses no fuel. For a discussion of fuel sources, see the fuel industry. The kiln does not allow you to select which type of ceramic to produce; instead, the potter will take the closest available material, be it ordinary clay, fire clay, or kaolinite. If no glazing is needed, this is the final step, and a skilled potter working a kiln can produce his/her goods at a steady clip.
Glazing is a process that covers a material in a coat of varnish, protecting it, making it shiny, and, as with other "embellishment" processes, adding to its value. If you have a lot of earthenware materials and want to use them for storing liquids, glazing is necessary; otherwise, it just makes your things more valuable. Glaze can be applied at a kiln to jugs, statues, large pots, and crafts made from either stone or ceramics, by a glazer.
There are two types of glazes: ash glaze and tin glaze. The first uses a unit of ash, produced by a wood burner at a wood furnace with the logs of felled trees. The second uses cassiterite, a relatively scarce ore only available if you have it on your map, and is thus sourced from your metal industry, where it may be more useful for smelting tin bars. Much like kaolinite, this is a mineral resource you may or may not have, but are lucky to get: where ash glaze is worth 50☼, tin glaze is worth 100☼.
The clay collection order occupies a kiln and requires the item hauling labor, not pottery or furnace operating. Since clay collection is time-consuming, you may start to see job cancellations as the potter's increasing skill outpaces his/her suppliers; to ensure a smooth process, either have multiple dwarves with item hauling enabled, or make sure you have a large gathering area and a large number of people with the job enabled (or both).
The biggest frustration with the ceramic industry is that you can't fine-tune what your dwarves will use through the kiln menu or the Manager's screen. You can't tell them exactly what material to fire or what kind of thing to glaze, only what to make and what type of item to glaze. This can be solved by using the 'give' and 'take' options within stockpiles. A stockpile next to the collection area will collect all the clay from a given source. A second stockpile, next to the kiln, can be set to 'take' from the first stockpile. If this second stockpile is set only to accept materials from the first, and to 'give' to the kiln, then the kiln will only use this single clay. If a kiln, or other workshop, has a stockpile set to 'give', then it must be supplied with all its required resources from other stockpiles set to 'give' as well. For the kiln this may be fuel, material for glazing or items to be glazed. The Stockpile page has further detail.
Another approach uses the fact that dwarves will go for the nearest available resource; make a stockpile right next to the kilns, choose what goes in there, and you can more or less force the potters to use one material over another, albeit with some tedium. This has the major disadvantage of requiring you to haul things back and forth when you switch orders, as dwarves will have to carry away the no longer needed material and carry in the newly desired one. Template:V0.34 industry