Matsushima, Iwao                             Artist's Main Page

 Core-Formed Glass:  A pre-blown glass technique used at the height of the Pharaoh's dynasties, then by the Greeks and  the  Romans

1- Various Aspects  of core-formed glass technique  
 

Canes, prepared by Iwao	Cores for various Vessels	M1B Core with relief, creating the wave and the final piece
Rainbow 1 Painting WITH the glass	Polishing Rainbow 2	M7 Applying the mosaic (left) and the canes. The vessel is in the center right

 Part I:An Overview, the Core & the Glass                                                                                       Artist's Main Page

This Technique section is not meant for artists to learn core-formed glass. It is for the lay person like me to understand and appreciate the technique beyond the esthetic appeal of the objects. That is why I am writing this part of the Catalogue. Iwao has been very patient and generous in providing detailed information and in guiding me through this text (the mistakes are mine). What I learned from him was beyond the technical aspect of core-formed glass, and I hope to convey that to the readers. The following pages show images of Matsushima at different stages of the work process. Some of the images are so clear that they will forgo the explanations that follow.

The major elements in Core-formed Glass are obviously the Core and the Glass. In a way, it is painting WITH the glass, where the core serves both as the canvas and its support, and the rods become brushes containing the colors.

The Core is a combination of steel wool and clay. The clay is such that it does not harden excessively on the flame, and is cored out of the vessel with relative ease. Theories abound regarding the composition of the cores used in antiquity. It is likely that they were a combination of strong plant fibers and clay according to Matsushima. On his cores, Iwao marks the design that will guide the rods and the canes. On some, he carves the relief pattern that results in what he refers to as the Mystery Code. (image below, detail of M1 Vessel)



The rods are the basic Glass elements that artists use to make Canes, Murrine and Beads. They come in different transparent or opaque colors. The Cane is an assembly of melted rods, pulled and twisted by the artist to create a particular pattern.  Iwao’s translucent canes are made by mixing transparent rods with plant ash. Kneading those thoroughly over the flame creates tiny seed bubbles in the resulting blob of glass. In a second stage more colored rods are added (without kneading) in order to make stripes or other patterns in the cane. That hot glass is then twisted and pulled resulting in a translucent cane having light transmission properties intermediate between the transparent and the opaque.  The process of making translucent canes resembles that of homespun yarn, hence the name Spin Cone for the vessel where these canes are used.  For Iwao, these Cones exude a particularly warm feeling.

The canes for the Murrine are made on the flame from the beginning to end. The initial cane is approximately 1.2” in diameter and 2.5” long (3 x 6 cm.). It is then pulled as a thinner cane from which the Murrine are sectioned. Iwao’s Murrine are stylized flowers, plants, butterflies, birds…This process is different from the Technique used by the Dei Rossis to create their Murrine. In the latter, the initial cold assembly is followed by the hot stage.

The Beads are oblong, disc-shaped or tubular (C4 & C5). Iwao hangs them from the vessel or places them on the metal base to suggest a water drop (M2).

Heating the Core with Markings	Painting WITH the cane	More canes used	The Lip	Smoothening
Removing the Core	Rough inside	Polishing the inside

Heating the Core	Painting WITH the glass canes		Smoothening	Applying a Cane
Applying more Canes	Smoothening the Canes	The Lip

 Part III: Various core-formed glass patterns                                                                                                 Artist's Main Page
 

Painting WITH a Rod	Marbleized pattern	Herring Bone pattern	Smoothening

Part IV: Distinctive Matsushima                                                                                                                Artist's Main Page

Although traditional core-formed glass is at the basis of Iwao work, he added significantly to the ancient technique.
Given the small size and the fragility of his vessels, Iwao does not sign them. His signature is on the elegant wooden boxes custom made for every piece, and it is on the metal that supports some of the vessels.
In reality, his signature is all over his work. Except when he intentionally and faithfully reproduces ancient pieces,
his core-formed pieces are easily recognizable as Iwao’s. Among Matsushima’s many contributions to this art form are: painting WITH the glass canes, the relief patterns (Mystery Code), the wavy pattern and the special use of the
Glass Beads

Matsushima creates for our enjoyment vessels with quiet but subtle shine and
with a particular harmony amongst the various glass colors