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We get a lot of questions pertaining to the variance in glass bead products.
Indeed, glass beads are a unique product because lots will vary significantly over time. Much
of this variance is inherent in the material and the manufacturing methods used to craft beads.
However, other irregularities are defects that should not occur under normal circumstances. The
following discussion will elaborate on the factors contributing to glass variance.
Glass Bead Manufacturing Methods
Lampwork
Lampwork beads are entirely handmade from molten glass around a metal mandrel, or rod. These beads
are made by adding design components over an open flame, or “lamp.” Lampworkers use various tools
to shape the bead and add effects. The nature of this process makes lampworked beads the most variable
glass products. Size and shape will vary due to the human factor. Color can also vary depending on
how long the glass material is heated and at what temperature.
Pressed
Pressed glass is made using different variations of molds. Molds are usually a component to a machine
press that is operated by an individual who activates the press with a foot pedal while feeding heated
glass into the machine molds. Pressed beads are much less variable than beads that are entirely handmade.
However, there is still a large human element to pressing.
Cut/Machine Made
Machined beads are produced using automated processes. These products will be the most regular over time.
The key variant in machine products will come from the batches of raw glass material. The raw material
lots are often the origin of color variation.
Coatings
Coatings are generally applied to glass beads as a final process step. Most coatings are sprayed on to
the surface while beads are on a conveyor system and then heat bonded to the bead, or vacuum deposited
at high temperatures. Coatings are more easily controlled and will often hide irregularities in the base
bead. However, if the coating is a glass material it will be subject to the same color variations.
Variance vs. Defects
Breakage
Glass is a fragile product and will break if it is not handled with care. Some breakage will occur in
shipping as products shift. However, breakage in transit is usually minimal. Exorbitant breaking or
cracking is usually due to poor annealing. Annealing is the process used to cool down the extremely hot
beads into solid glass after they are formed from molten glass. If beads are cooled too quickly they
will react much like ice and crack. These cracks may remain internal or they may break the bead apart
entirely. Proper annealing takes time and skill. High quality beads are professionally annealed. However,
you will see that annealing is not as good in economy products since they are mass produced with less
attention to detail.
Color
Glass is a unique material. Chemically, it is extremely hard to make identical glass colors from batch
to batch. Each color has a unique chemical signature. Slight alterations, contaminants and inclusions
can change the hue. The difficulties from creating certain colors stem from the difficulties in
controlling the additive purity. For example, you will notice that red glass items are often more
expensive. This is because red glass is more difficult to make.
Difficulties in color consistency are exacerbated by supply shortages in the glass rod industry. The
wide palette of glass colors is not always available and manufacturers will move up or down in shade
to smooth out production schedules and avoid shortages. Color can also vary greatly from lot to lot as
the beadmaker obtains glass from various sources over time.
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