When to use Rayon/Viscose and when to use Polyester thread?

MADEIRA CLASSIC VISCOSE RAYON:

ORIGIN: Natural fibre from trees
APPEARANCE: Very brilliant; Smooth soft sheen; Natural living silk
TOUCH: Soft
MARKET SEGMENT: Fashion/Sports led & orientated
STRENGTH: High tensile strength, with high wet strength compared to cheaper viscose
EMBROIDERING: Easy, very flexible thread, precise, clear embroidery
MACHINE SPEEDS: High speeds
THREAD BREAKS: Minimum
RESIDUE: Very little – clean thread
AUTOMATIC THREAD TRIMMERS: No problems
BACKGROUND FABRICS: All possible
HEAT CUTTING (EG FOR BADGES/APPLIQUÉS): No problem
QUALITY: Highest Quality – to International ISO, DIN & M&S standards
ENVIRONMENTAL ISSUES: Oeko-tex Class I Certification
RANGE: 413 Colours, including 58 ombré & multicolours and 5 different black colours
THICKNESSES AVAILABLE: 30, 40 (standard) & 60
PRICE: Slightly more expensive than Polyneon, but minimal increase on cost per 1000 stitches; Runs fast on machines so production time reduced
AVAILABILITY: Worldwide
FLAMMABILITY: Slow & even
WASHING: 95°C; Standard detergent wash
MULTI-WASHING: In general, no problem – durability of Madeira’s high tensile viscose is better than cotton or wool
IRONING: Iron @ •• 210°C

 

MADEIRA POLYNEON POLYESTER :

ORIGIN: Manmade fibre from oil
APPEARANCE: Brilliant; More artificial sheen
TOUCH: Harder
MARKET SEGMENT: Promotion & Badge orientated
STRENGTH: High strength – too strong for some applications
EMBROIDERING: More difficult until tension adjusted; Clarity not guaranteed on fine detail
MACHINE SPEEDS: High speeds but see below
THREAD BREAKS: Sometimes more
RESIDUE: Some, as dyestuffs sit on, not in, the fibre
AUTOMATIC THREAD TRIMMERS: Do not always work, causing more downtime & difficult to snap by hand
BACKGROUND FABRICS: Not for very fine or dense fabrics
HEAT CUTTING (EG FOR BADGES/APPLIQUÉS): Not recommended, as polyester melts at 200°C
QUALITY: Highest Quality – to International ISO, DIN & M&S standards
ENVIRONMENTAL ISSUES: Oeko-tex Class I Certification
RANGE: 359 Colours, including 10 Astro colours
THICKNESSES AVAILABLE: 40 (standard)
PRICE: Slightly lower priced – possible future changes due to world oil situation;  Stock value increase implications as viscose predominantly used/stocked
AVAILABILITY: Worldwide
FLAMMABILITY: Fast melt & “explosive”
WASHING: 95°C, Heavy duty detergent/bleach washing, chlorine & stonewashing*
MULTI-WASHING: No problem  
IRONING: Iron @ •• 140°C