Mark Lauckner artist in glass
The Glass Foundry

Fused Mosaic Glass (Venitian Style)

I make two different types of Venitian style fused mosaic glass.  One style is made with commercial glass imported from Italy, and the other style is made from patterned glass rods and canes which I produce in my shop from recycled glass.  There is quite a bit of difference in the density of the colours between the two, so the imported Italian glass tends to used to produce the rich, opaque coloured pieces, and my own funky & chunky canes tend to be the dishes with coloured patterns in a clear base.

This style of fusing and shaping glass patterned cross-sections dates to around 900 AD.  In Italy, pieces have been excavated from Roman ruins from around 1300 AD.  This style was re-popularized in Venice glassmaking in the 1700's.  Now it is known as "Venitian" or "Millifiori" glass.  The Italian word "millifiori" means "thousand flowers".  When one of the patterned canes is stretched out and chipped up into little pieces, it is possible to get over 1000 small flower patterns from each "pull".

Following is a description of the procedure I use for the creation of these items.  First, I'll use the small dishes as an example for the imported Italian glass procedure.

Click on photos to see enlargements
Glass rods - colour combinations
Rods are chipped up into pieced
Assembing the outer ring of mosaic

Selection of colours  

chipped up pieces

assembling the outer ring

Day one: As the rods and canes are already made, the procedure starts with the selection of colours and patterns for the intended design.  The rods are chipped up into pieces and assembled in a circle, forming the outer rim of the dish.  This is done on a ceramic kiln shelf coated in powdered clay.  Glass is very sticky when melted, so the powdered clay helps to prevent it from sticking to the flat shelving.  Then the ring is fused together in a kiln at 1500 degrees F.  It is cooled slowly, overnight, to prevent cracking.

Fusing the glass outer ring in the kiln
Finished glass outer ring
Filling inside the ring

fusing the ring in a kiln

the finished ring

filling the inside with pieces

Day two: The area inside the outer ring is then filled with the remaining pieces.  For these small dishes under 4 inches in diameter, over 280 pieces are required.  Larger items require several more hundreds, even thousands of pieces.  I fuse the outer ring first, and then assemble the inner area.  This takes an extra day, but results in a smooth division between the two colours.  This is because the glass rods are round, and when they melt together, they sink down and fill the voids between them.  This results in square or 5-sided looking coloured divisions.  I don't like this feature in the dishes, especially in the outer colour band.  Fusing the outer band first fills most of the void between the pieces with the intended, outer colour.  (Below is an example of two clear dishes with white rims. The one on the left was all fused at the same time, and the one on the right had the outer rim fused the day before.)

Close up of glass ring
mosaic ready to be fused
Fused mosaic disc

pre-fused ring on right

pieces ready for fusing

fused disc

After all the inner pieces are tightly fit, then it's back into the kiln for fusing.  Again, the whole thing is fused at 1500 degrees F, and then cooled slowly overnight.  The result is a flat pancake-looking disc of glass.  But, as there is significantly more volume this time, the kiln is dropped quickly from 1500 and held at 900 degrees for a couple hours before the slow cooling, to anneal the glass.  This prevents it from breaking the next time it is heated, during the shaping.  Pictured on the right is a flat disc made during the kid's "Glass Camp" summer classes in 2001, and is now ready for shaping.

Sandblasting booth
Shaping the glass disc
Finished Glass Bowl

sandblasting booth enclosure

shaping the disc on a form

4 days later: the finished dish

Day three:  The piece is prepared for shaping by sanding the edges in a water-cooled machine, and often by texturing the back by sandblasting.  Above left is my custom-designed sandblasting booth, large enough to run in shower doors and large window panels.  This surface frosting is something I like to do on the transparent dishes to provide a visual barrier on the back of the piece.  (This way, you don't see through the pattern to the table the dish is sitting on.)  I often sandblast the surfaces of the opaque dishes as well, for durability, as the textured surface is less prone to scratching.  (Sandblasting before the final heating ensures that the surface texture will not be coarse enough to collect dirt and finger oils.) Next is a photo of the stainless steel form the disc is slumped into.  This final kiln firing requires very slow heating until 1000 degrees F, then rapid heating until 1200 degrees, with constant manic kiln-peeking, then rapid cooling back to 900 degrees, in order to stop the shaping at the precise position.  After holding at 900 degrees for a couple hours for final annealing, the piece is cooled slowly overnight.  Day four: unloading the kiln.

Part Two: My procedure for making my own patterned canes and the resulting plates and bowls.  (Coming soon!)

(Coming Soon - mosaic dishes, plates and bowls for sale)

Collection of Mosaic Glass Bowls and Dishes


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last update
December 12, 2013