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Seed Beads

How Miyuki Glass Seed Beads Are Made

In April 2000 I visited the Miyuki glass bead factory in Japan. My tour was fascinating and the information below is what I gleaned from touring the factory. I was not invited to photograph most of the process, sorry. -bk

How Miyuki Glass Seed Beads Are Made

Step One: Raw materials and recycled glass of the same color are mixed and melted in the furnaces. The Miyuki factory has both automatic and manual furnaces operating 24 hours per day. They are on the 2nd floor.Step Two: When ready, molten glass from the furnaces falls through a hole. The shape of the hole determines the shape of the glass tubes. Compressed air hitting the center of the glass column turns it into a hollow tube of glass. Step Three: After dropping to the first floor, the vertical tube of falling glass passes under a thick chunk of wood and turns at a right angle to become horizontal. Imagine a vertical length of rope passing under a pulley and then being pulled sideways. The scene in the glass factory is much more dramatic, however. For starters, the glass "rope" is still extremely hot so that it is slowly burning its way through the smoking piece of wood. In addition the tube of glass is actually being pulled over a series of metal troughs by a machine which not only pulls the glass but also cuts it into one meter lengths. The speed of the pulling determines the diameter of the glass tubes. A faster pull makes thinner tubes; a slower speed makes them thicker.Step Four: The cooled tubes are sorted to make sure that they are the correct diameter for the size beads being produced. Any tubes which are not the correct size will be recycled and remelted to make new glass.\ Step Five: The tubes are cut into beads. As the cutting room is not open to any outsiders, I can't offer further information. I did learn that one Delica cutting machine can only cut 4-5 kgs per day, which is one reason for their high cost. (And contrary to some rumors, Miyuki cannot run the Delica cutting machines faster to keep up with increased demand, with an accompanying decline in quality. Instead high demand just leads to longer waits for production). Delicas are not cut by lasers, by the way, another occasional rumor. Step Six: Cut beads are mixed with carbon black and reheated to make them round. Delicas are only slightly heated; round beads are heated more.Step Seven: The beads are washed. Miyuki has their own on-site water treatment equipment. Step Eight: The beads are heated again to give them a surface polish. Basic opaque and transparent beads are now finished and ready to pack.Step Nine: Fancier beads - AB colors, silver and color-lined, metallic, etc. - are based on the basic opaque and transparent colors. There are several different locations in the factory where dyes and other coatings are applied. Some beads require multiple treatments which directly influence their final cost. After dyeing or color-lining beads, Miyuki reheats them again to "set" the colors, a step skipped by some bead companies to reduce costs.

Miyuki Delica Seed Beads List Sample Card

This is a sample card for Miyuki size 11 delica seed beads gleaned from several sources and ordered by manufacturer number in PDF format.

Miyuki Round Seed Beads List Sample Card

This is a sample card for Miyuki size 11 round seed beads gleaned from several sources and ordered by manufacturer number in PDF format.

The Wonderful World of Seed Beads

The term seed bead refers to an entire category of small, usually glass beads that have been used for adornment for over 200 years. The first glass seed beads were made and strung by hand in Italy in the early 19th century. Most of the seed beads in production today are manufactured in Japan or the Czech Republic in the area that was once known as Bohemia. Czech seed beads are used in traditional Native American regalia and require a high level of skill to work with. Seed beads that are produced by the Japanese are much more uniform in shape with typically larger holes than Czech beads which are have slight irregularities that give them a more organic look that many people prefer in their designs.

Czech seed beads come in a variety of shapes from the long bugle tube to the traditional charlotte that is faceted on one side to add sparkle. Japanese seed beads are mostly made by two companies, the Miyuki Shoji and Toho, and though they come in a variety of shapes the cylinder shape has become increasingly popular in the beading community. Miyuki’s cylinder beads are called Delicas while Toho has 2 cylinder beads, the Treasure bead and the newer, updated version, the Aiko. Lining up straight to create a woven tapestry effect, cylinder beads are exceptionally precise in all manner of stitches such as Peyote, Brick Stitch and the Herringbone weave. Cylinder beads make pattern designs come out accurate and even and also give curved stitches such as the Dutch Spiral or Rosette a more angular shape. Japanese seed beads in particular are unique from one dye lot to another but come in the most specialized rainbow of colors with legendary finishes that are obtained by treatments such as etching, galvanized metal coatings and metal linings to name a few.

Seed beads are typically sold by the hank (a group of strings) or by weight (loose in a tube or bag). Possibly the most popular size today in both Czech and Japanese seed beads is the 11 but seed beads can be found from a 5 or 6, (being the largest), up to 22 or 24, (the smallest). Below is a chart that shows the recommended needle and thread size for different sized seed beads, and for more detailed recommendations, please see our Beading Resources article in the Library section.

Seed beads are also frequently used as spacers in straight stringing and mixed media projects. We at Harlequin know the importance of having a full palette of colors and textures of seed beads so we are constantly updating and increasing our already impressive selection of these important little treasures. Be sure to check our collectible bead section for rare antique seed beads as well, and happy beading.seed bead chart

Seed Bead Chart

[click on image to enlarge]