|This article is about an older version of DF.|
The Glass Industry is a versatile and, under the right circumstances, sustainable source of items. Everything from finished goods to furniture to low value glass gems to blocks to trap components can be created in glass, making Glassmaker a very useful profession. Since glass is magma-safe and capable of producing all necessary screw pump components, a glassmaking industry can prove quite valuable when working with magma.
The limiting factors to glass production are sand and fuel; in order to produce glass in great quantities your map must have sand (any single tile has an infinite amount of sand) and either a good source of coal, magma or many trees. Small quantities of sand can regularly be acquired from caravans, but rarely enough to run a large industry. Soil layers may or may not include sand; there is no way to tell if your map will provide it until you embark (other than cheating). If you want to ensure the possibility of a flourishing glass industry, embark on a sand desert or badlands biome. Keep in mind these biomes by themselves don't have trees to fuel your furnaces early on. Another option is to embark adjacent to an ocean, as the beaches are usually composed of sand, but this usually results in fighting the aquifer that predictably accompanies a coastline, lengthening the time until it takes to mine down to the magma sea.
To make items from glass, sand must first be gathered in bags using a task available at any glass furnace, "Gather Sand". You must designate a Sand Collection zone from the ()-menu that includes an accessible area of sand in order for this task to be performed. Only cut glass "gems" (and artifacts) can be made from raw glass purchased from caravans. All other glass objects must be made from "sand bearing items", i.e. bags of sand.
All sustainable types of glassmaking require a bag of sand. The "Collect Sand" order at the glass furnace requires the "item hauling" labor, not glassmaking. The Collect Sand order does however still occupy the glass furnace, preventing glassmakers from performing any other jobs there until after the collection has been completed. Collecting sand is a time consuming task, and proficient glassmakers quickly become faster at making items than gathering materials, leading to job cancellations as collected sand becomes scarce.
Sand for glass can only be collected from collection zones placed on floors made of "Sand (tan)", "Black sand", "Red sand", "White sand", or "Yellow sand". Any sandy soil type with "Loam" or "Loamy" in it will not work for glassmaking.
Collecting sand efficiently
There are ways around this problem, each with its own benefits and drawbacks.
Collect a specific amount of sand bags, then assign the correspondent orders of actual glass making. This ensures that enough bags remain for other tasks and no cancellations happen. It is also the best way to keep an overview of what has actually been produced, especially when using the manager. Time loss is negligible as the bulk of time is consumed by hauling sand.
The fast, somewhat sloppy method is to build additional glass furnaces near your sand collection zone for the sole purpose of repeating the Collect Sand order while other furnaces are used for actual glassmaking. You can prevent the manager from assigning work order jobs to this furnace by using the workshop profile to disable general work orders.
- This method will free up time for your glassmakers to focus on making glass items.
- It is possible to turn off all of your craftsdwarves' hauling labors and let your pack of otherwise useless Potash Makers do all the grunt work of filling bags.
- This method is hard to balance. Just when you think you have found an equilibrium between supply and demand, a legendary glassmaker goes to sleep and every bag is filled with sand during his absence, resulting in a cascade of canceled bag filling jobs. If you instead order more bags than can be used, hundreds of surplus sand bags will accumulate until you eventually run out of bags or tweak the balance again.
Slow and easy
The slightly slower but more controllable method of collecting sand efficiently. Assign each glass furnace to an individual glassmaker, and make sure that the dwarf's item hauling labor is turned on. Stagger work orders so the glassmaker hauls their own sand, then makes their item, then hauls their own sand.
- Orders can be set to repeat endlessly in the background with no oversight, which is particularly excellent when mass-producing raw glass or blocks.
- Tandem job orders like this mean that only five orders can be placed at a time, meaning that orders are placed most effectively as repeats. A way around this is to set five different types of tandem orders and suspend and unsuspend them as desired.
- This method is slower than the brute force method, and doesn't give your horde of idle dwarves anything to do.
- The manager can still be a burden with this system and ruin the balance of labors.
Varieties of glass
- Producing crystal glass requires no sand, but does require pearlash and rough rock crystals, a gem which is not found on all maps. Cut rock crystals bought from traders will not work for producing crystal glass. Crystal glass is worth ten times as much as objects made from most stones, making it equivalent in value to metals like silver.
See also "Glass" for a full discussion of the properties of glass items.
Glass Industry Flowchart
Glassmaking vs. other professions
Functionally, the glass industry is like a cross between the stone industry and the metal industry, incorporating elements from both. Functionally, it is similar to metalworking, using a furnace and fuel to produce its products, and its products can have material values similar to metals. Meanwhile, its actual product output is most similar to stoneworking, with only a few differences, and it can pretty much fully replace masonry except for those instances.
There is considerable overlap between items produced from stone at a Mason's workshop, and items produced from glass at glass furnaces. Masonry is easier to get running and will clear excess stone from your fortress. Glass produces items with a higher base value (unless you make your masons use flux or obsidian), and using a magma glass furnace allows you to make green glass objects without consuming anything but dwarven labor. Glass also provides a magma-safe alternative, to prepare for magma-based projects before it's discovered or avoid stockpile micromanagement for the correct building materials. Unique stone products which cannot be made of glass are querns/millstones, slabs, crafts, and stone short swords.
There are many similarities in the processes between metalsmithing and glassmaking. Both require fuel, and both require supplementary materials for certain unique products. Additionally, crafts are made directly at the furnace, rather than at a craftsdwarf's workshop. Metalworking is generally more likely to be started first, as any site will eventually find metals and fuel, (if even only in the form of magma) and quality weapons are often needed to start a military, but how much you can make is limited by how much you can dig up or buy. Glassmaking has the potential to produce infinite products, if given sand, enough bags, and magma. Also, while metal ores are turned into an intermediary material, (bars) by another profession at a different workshop, which must then be forged into a product, glassmaking produces a product directly from the raw materials, and still leaves you with an empty bag. Finally, metalworking has a far more diverse range of products, including restraints, weapons, and armor.
In a typical fortress, magma is located deep below, while sand is a soil layer and thus without some creative management is just below ground. Without minecarts, each sand bag will be carried by a single dwarf, thus requiring a lot of dwarf labor and wide staircases. With minecarts one can not only transport a lot of sand bags to the magma furnace without much dwarftime wasted on hauling, but also transport all the glass products back up. If set up, the track can be also used to supply (and grab from) magma smelter which is likely to be located close to magma glass furnace. If one is too lazy to set up a track, minecart system can be easily used simply to haul all the sand bags in a convenient container (requires a wooden minecart). If both endpoints are set to guide, but are left disconnected, dwarves will just grab the minecart and haul it to destination. Since sand bags and wooden minecarts are both reasonably light, the dwarf won't slow down much. Another solution if you have an iron (magma safe) mine-cart is to use it to haul magma up and dump it in a channeled tile in your sand level. If you then build a magma glass furnaces on top of that magma you can avoid multi z level hauling since your entire glass industry will be in one location.