Glass is an impressive substance, it has existed since beginning oftime in forms of natural black volcanic glass known as obsidian and now it isall around us in different sizes, shapes, colour, translucence and transparencies.Romans were one of the best skilled glass makers who held most secrets but whenthe Roman Empire started to fall those secrets began to be revealed and theirideas spread into parts of Europe and the Middle East.
Venetians after the fallof Romans became the most skilled and successful glass makers in Europe withtheir Murano glass, mainly because of their secrets and popularity among the neighbouringregions. But if it wasn’t for the first discovery of glass around 4,000 yearsago, none of the above would have been possible and today’s society would havean alternative, maybe for the worse or for the better. But nonetheless, all theresearch through out centuries have brought us to the point of being able tofuse glass together and create remarkable pieces of art. Theory:In comparison to materials such as metal or clay, glassbehaves very differently when its being heated and cooled. Glass is neither aliquid or a solid hence why it may be considered a supercooled liquid becauseof its atom arrangement, when its temperature is being lowered below thefreezing point it’s not going to become a solid. For example, compare how waterchanges into solid ice below 0oC, whereas glass will remain a liquidbelow minus temperatures. With this you may argue that glass is never a solidalthough it may look and feel like it is.
A glass window which is in a vertical position for a longperiod of time will become thicker at the bottom. This is because of its liquidstate where gravity will pull the glass atoms downwards, but glass atoms movetoo slowly for us to see any changes. 1 Glass can also handle being heated tovery high temperatures because of its random molecular structure of a liquid.
(Dan Klein and Ward Lloyd, The History of Glass) It is also very fragile so when it is notbeing cooled under a specific method and slowly, it can shatter and crack if itis exposed to sudden changes in heat. 2 This is also because of its randommolecular structure. Origins:There is little information on the origins of glass makingbut it is believed its first attempts were discovered around 4,000 years ago inMesopotamia, todays Iraq and parts of Iran, Syria and Turkey. 3 First glassmaking goes back to Phoenician sailors who discovered it by accident as accordingto a Roman historian Pliny (AD 23-79). He states that the sailors landed on abeach near Ptolemais and needed to cook their food, but they could not find bigenough rocks on the beach to place their pots on so instead they used blocks ofnatron which they were carrying as cargo. Natron is a type of naturally occurringalkali substance also known as a form of soda. When their food was finishedcooking, they found that natron fused with the sand which created a liquidstream that later cooled and hardened into glass 4 This is a strangeexplanation because the fire would not be able to reach the required meltingtemperatures. The first basicrecipe used to make glass was discovered around 3,500 BC in eastern Mesopotamia,this idea is more accepted than the sailors discovering it.
5 The ingredientsused were a mixture of silica from sand, lime and soda which is an alkali. Whenthe mixture is heated it becomes soft and could be formed into various shapes usingdifferent techniques (Fig 1). One of the techniques to make the glass into acertain shape was to place the molten glass into a mould and allow it to cooland harden. This way of making glass was used right until the inventionof lead glass by George Ravenscroft in late 16th century.
This methodconsisted of adding lead oxide which made the appearance of glass better andmade it easier to melt using coal. 6 After the discovery of glass inMesopotamia, glass makers started to craft the first hollow vessels as early as3,000 BC (Fig 2), but before that other glass objects were made such as tiles, pottery and beads being most popular. The glassvessel shown on the left was one of the first to be made, their shape refers toa pottery form. They were made by creating a temporary core and pouring meltedglass around it. We can also see that it was painted on the outside withdifferent shapes which could refer to a historical or a special event but becauseof time those markings are gradually starting to fade away. If you compare thispiece of art to modern glass, you can see how far we’ve come in termscreativity, method and technology. Glassmakers during this time played an important role forthe kings and other powerful people. The glass they made was too expensive tobe bought by the local public.
Royalties enjoyed showing off the power andwealth with their invention of glass, often beads and vessels like the oneshown in Figure 2 were made for special occasions such as weddings, ceremoniesand gifts to other powerful individuals of Mesopotamia and other regions. Glassjewellery was also popular and was commonly worn by the royalties during importantevents. Roman Glass:Glassmaking was very difficult and labour intensive so only the wealthy were able tobuy it. It was not until the discovery by the craftsmen in the Roman Empire in FirstCentury BC which made the glass objects more affordable. This method consistedof inflating a gob of glass on the end of a hollow tube, also known as glassblowing (Fig 3) it allowed thecraftsmen to create more shapes and experiment with what they could create. The technique was simple, could easily be understood andreplicated. In modern glass blowing the difference is the glass was again heatedand inflated, shaped during the process and cooled slowly while rolling it onthe workshop’s bench made of metal which made the glass inflate more and then shapedfurther with tools until a specific shape was achieved.
During the second processafter the glass has been heated again you can dip the gob into crushed colouredglass and begin to roll it again and heat it several times until the desiredcolour is visible. (Dan Klein and Ward Lloyd, The History of Glass) Roman glassmaking taste often changed depending on thehistorical events that have occurred throughout the years. The decorations andcolour combination could change depending on what the new trend is at the time.In World of Glass Museum, the Roman glass section, I have seen differentdesigns and shapes and all of them were from different time periods. Since glass was cheaper and more available to the public, itcould be used such as cutlery, pottery, dishes, wash basins etc. for domesticpurposes.
Since Rome had plenty of skilled glassmakers, they could make simple objectsin vast quantities. On the other hand, a wealthy lady may want a small,beautifully decorated glass container to store her perfumes. Jewellery alsoplayed a part just like in the Mesopotamian time where the rich would wear thebest glass jewels to show off their wealth. The Romans are stillknown for their beautiful and expensive glass which was mainly used fortableware, perfume containers and even jewellery.
7 Figure 4 (taken from theWorld of Glass, St Helens) shows more simplistic Roman glass. By the shape andcolour of the objects we can identify that the glass must have been dipped intodifferent colours during the heating process then melted and placed into amould and left to cool for a specific amount of time. I could also noticeduring my visit at the museum that most Roman glass have a blue and whitecolour combination. The Morgan Cup was made during the1st century and is one of the rarer objects of the early RomanEmpire. This glass object was created within the 100 years of the invention of Romanglass blowing. It must have taken a lot of skill and time to create. The cupconsists of 2 or 3 layers of glass with white being on top of blue.
This musthave been the popular combination of colour at the time because we can also seethe same combination in Figure 4. This side of the cup which shown in Figure 5represents “young female wearing a short tunic and an ankle-lengthdress. She kneels and lifts a cloth from a cylindrical box. The next figure isa young male.
He is wearing a loincloth tied at the waist, and he fastens oneend of the canopy to the column.” – 8. The corning museum best describes thispiece of art and to my knowledge this side of the cup is meant to represent thedaily life of a lower class Roman citizen but there is a longer story anddeeper meaning behind the markings. Venetian Glass:The fall of the Roman Empire in 476 AD lead to many glassmaking secrets to be revealed. Those secrets eventually spread into the eastand Europe making its way to Italy.
Venice eventually made itself a popular glassmaking centre in the 8th century and one its major factors is itsgeographical location which enabled trade links with Europe and the ByzantiumEmpire. By 12th century, venetian glass was at its finest qualityand was one of major city’s industries. Unfortunately, there are no examples ofVenetian glass before the 15th century. Since the venetian glass wasat its top quality, a Glassmakers Guild was created to keep the secrets of the tradeso Venice will ensure its profit for as long as possible. The guild was also incharge of setting out rules for the glassmakers, one of the rules was toprohibit the employment of foreign workers so the secrets could never berevealed to other countries. There was also a ban on the import of any foreignglass. Another law was later introduced which disallowed the glassmakers toleave Venice, in return, the craftsmen were greatly rewarded for their effortsand success.
Despite these controversial laws and guidelines, this is the firsttime to see glass making to be made important again since the Roman times. 9The main workshops and glassmakers later moved to an Islandnamed Murano, very close to Venice. Venetian glass became very popular in the 15thcentury, it was also during this time a master craftsman discovered how tocreate clear glass which eventually allowed Murano glassmakers to createmirrors. Figure 6 on the left shows an example of Murano Glass, Barovier Cup,which was made for a wedding. There is enamelling on clear glass which waspopular at the time.
One side of the cup art shows people on horseback andother side women who is going to bathe in a fountain. 10 We can also see theexample of clear glass on the stand. During 17th century, the Murano glass slowlyentered a decline, its exports and sense of importance around the tradingroutes began to vanish. Most traders and buyers in the 17th centurywere no longer interested in the glass work.
Overall this caused a decline inthe production of glassmaking in Venice all together. The gradual decline mighthave been due to the cause of other glass works being established around Europewhich had a different style that was more custom to the region. Butsurprisingly new techniques of Murano glass started to be developed that wereassociated with the current art theme at the time in Europe which kept theglass work alive, for the time being.
In 18th century the decline and Napoleon’s markon Venice made it impossible for glassmakers to continue their craft andultimately bringing death sentences to all Murano glassmakers. This shrank theindustry entirely and only few furnaces remain in Venice that were only usedfor glass blowing. 11 But we can see that Napoleon did not truly succeed inhis abolishment because we can still see example of Murano and other Venetianglass art today. In 19th and 20th century the craft continuedwith new techniques and discoveries of production, but this era mostlyconsisted of the re-production of the classic Murano styles and by this timesome Italians left to create their own glassworks around Europe. Fused Glass:It is believed by researchers that fusing glass together wasused as a technique in Egypt around 2,000 BC. This technique was used beforethe discovery of glassblowing in Rome. This method was mainly used for fusingsmall pieces of glass together and once the discovery of glassblowing and itsefficiency, glass fusing became less popular. It was mainly ignored until the19th century in America where fusing became a style in fine art andother interests.
12Figure 7 shows how askilled glassmaker can create interesting patterns on fused pieces of glass. Thisdesign was created by having different shades of green on 2 or 3 sheets of glassand placed into a kiln. After the glass was fused together it went through aprocess of slumping where the melted glass is placed into a mould and heatedonce more creating the shape and soft edges of the object. It is then left tocool and taken out of the mould.
Before making fused art, it isimportant for your glass to be compatible or to be tested before use. Thismeans that the piece of glass you will be working with has been properlyidentified and you know it’s safe to use. Glass that has not been tested oridentified may produce certain toxic gases when heated or unexpectedly shatterunder certain conditions you are required to work with. Your Kiln will also berequired to be properly washed so there are is no left-over material from previoussession. Once you have prepared your kiln and kiln shelf, it is ready forfiring.
Before cutting glass, you may needto design a pattern, shape or an idea that you would like to create. Createyour design on a piece of paper, note that if you want to use multiple piecesof glass you may need to make more designs. You