, a component of rosin • It is rubbed on the hair of
bows for
bowed string instruments to increase friction. • It has been used for centuries for
caulking ships. • It is approved by the US
FDA as a miscellaneous food additive. • It is an ingredient in
printing inks, photocopying and laser printing paper,
varnishes,
adhesives (glues),
soap,
paper sizing,
soda,
soldering
fluxes, and
sealing wax. • It can be used as a
glazing agent in
medicines and
chewing gum. It is denoted by
E number E915. A related
glycerol ester (E445) can be used as an
emulsifier in
soft drinks. In
pharmaceuticals, rosin forms an ingredient in several plasters and ointments. • In industry, rosin is a
flux used in
soldering. The
lead–
tin solder commonly used in electronics has 1 to 2% rosin by weight as a flux core, helping the molten metal flow and making a better connection by
reducing the refractory solid
oxide layer formed at the surface back to metal. It is frequently seen as a burnt or clear residue around new soldering. • Rosin is also sometimes used as internal reinforcement for very thin skinned metal objects – like silver, copper or tin plate candlesticks, or sculptures, where it is simply melted, poured into a hollow thin-skinned object, and left to harden. • A mixture of
pitch and rosin is used to make a surface against which
glass is
polished when making optical components such as
lenses. • Rosin is added in small quantities to traditional
linseed oil/sand gap fillers ("mastic"), used in building work. • When mixed with waxes and oils, rosin is the main ingredient of
mystic smoke, a gum which, when rubbed and suddenly stretched, appears to produce puffs of
smoke from the fingertips. Rosin is extensively used for its
friction-increasing capacity in several fields: •
Ballet,
flamenco, and
Irish dancers are known to rub the tips and heels of their shoes in powdered rosin to reduce slippage on clean wooden dance floors or competition/performance stages. It was at one time used in the same way in
fencing and is still used as such by
boxers. •
Team handball players use it to improve grip.
Rock climbers have used it in some locations. •
Olympic weightlifters rub the soles of their weightlifting boots in rosin to improve
traction on the platform. • It is applied to the
track surface at the starting line of
drag racing courses to improve traction. •
Bull riders rub rosin on their rope and glove for additional grip. •
Baseball pitchers and
ten-pin bowlers may use a small cloth bag of powdered rosin for better ball control. Baseball players sometimes combine rosin with sunscreen, creating a very sticky substance that allows far more grip on the ball than the rosin alone will; the use of such a substance is a violation of
Major League Baseball rules. • Rosin can be applied to the hands in aerial
acrobatics such as
aerial silks and
pole dancing to increase grip. plate covered with powder resin Other uses that are not based on friction: •
Fine art uses rosin for
tempera emulsions and as painting-medium component for
oil paintings. It is soluble in oil of
turpentine and turpentine substitute, and needs to be warmed. • In a
printmaking technique,
aquatint rosin is used on the
etching plate in order to create surfaces in gray tones. • In
archery, when a new
bowstring is being made or waxed for maintenance purposes, rosin may be present in the wax mixture. This provides an amount of tackiness to the string to hold its constituent strands together and reduce wear and fraying. •
Dog groomers use powdered rosin to aid in removal of excess hair from deep in the ear canal by giving the groomer a better grip to grasp the hairs with. • Some brands of
fly paper use a solution of rosin and rubber as the adhesive. • Rosin is sometimes used as an ingredient in dubbing wax used in
fly tying. • Rosin is used hot to de-encapsulate
integrated circuits encapsulated in
epoxy. • Rosin can be mixed with beeswax and a small amount of linseed oil to affix reeds to reed blocks in accordions. Rosin and its derivatives also exhibit wide-ranging pharmaceutical applications. Rosin derivatives show excellent film forming and coating properties. They are also used for tablet film and enteric coating purpose. Rosins have also been used to formulate microcapsules and nanoparticles.
Glycerol,
sorbitol, and
mannitol esters of rosin are used as
chewing gum bases for medicinal applications. The degradation and
biocompatibility of rosin and rosin-based biomaterials has been examined
in vitro and
ex vivo.
Rosin soaps and esters Treatment of rosin with sodium hydroxide or sodium carbonate converts the abietic acid into its sodium salt, which is known as a soap. Whereas most domestic soaps are sodium salts of straight-chain fatty acids, the rosin soaps have the branched and cyclic backbone associated with abietic acid. Rosin soaps, also called rosinates, are used to "size" paper, a process that gives paper a desirable hydrophobic texture. Occasionally, substances such as
beeswax,
gold,
silver,
tin, or
meteoric iron are added to the rosin to modify its
stiction/
friction properties and the tone that can be produced. Powdered rosin can be applied to new hair, for example with a felt pad or cloth, to reduce the time taken in getting sufficient rosin onto the hair. Rosin is often reapplied immediately before playing the instrument. Lighter rosin is generally preferred for violins and violas, and in high-humidity climates, while darker rosins are preferred for cellos, and for players in cool, dry areas. There are also specific, distinguishing types for
basses. • Violin rosin can be applied to the
bridges in other musical instruments, such as the
banjo and
banjolele, in order to prevent the bridge from moving during vigorous playing. The type of rosin used with bowed string instruments is determined by the diameter of the strings. Generally this means that the larger the instrument is, the softer the rosin should be. For instance,
double bass rosin is generally soft enough to be
pliable with slow movements. A cake of bass rosin left in a single position for several months will show evidence of flow, especially in warmer weather. == Production ==