|This article is about the current version of DF.|
Note that some content may still need to be updated.
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; the embark screen should display "Sand" when the embark contains any. 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" labour, not glassmaking (i.e. setting a custom work detail for glassmaking will not stop other dwarves from completing a collect sand task at a glass furnace). 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.
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
Due to the work order rework from May 2016, setting up automatic collect sand orders is fairly simple. The steps to do so are as follows:
- Create a new work order to Collect Sand.
- Enter the set conditions menu for the order, and add two new conditions.
- In the first condition, click Type, then enter "bags". Then click Adj and enter "empty items". You may be sent back to the work order menu when you hit escape, so re-enter the Collect Sand task. Now set the number to something reasonable (if you don't want too many job cancellations, set it higher than the number of times the order is set to run (default is 10). The first condition should now read: "Amount of empty bags available is at least 10".
- In the second condition, click Adj and enter "sand-bearing items". You may also enter the Type "bags", but it is not necessary. Now set the number to the number of bags you wish to keep on hand at any given time. Finally, set the inequality to "less than" or "at most". The second condition should read: "Amount of sand-bearing items available is less than 20".
I would recommend setting this work order up in a dedicated glass furnace next to your sand collection zone so as not to interfere with glass production. To do this, click on your glass smelter, click on Work Orders, set general work orders allowed to zero, then follow the above steps, clicking on the create new work order button inside the shop instead of in the main Work Orders menu.
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 labour and wide staircases. With minecarts one can not only transport a lot of sand bags to the magma furnace without much dwarf-time 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 their 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) minecart is to use it to haul magma up and dump it in a channelled tile in your sand level (video tutorial linked here). If you then build 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.