Which Thread? Viscose Rayon or Trilobal Polyester?
One of the most frequently asked questions in embroidery is “Which thread to use? Polyester or Rayon?" In many cases people give answers slanted towards whichever thread type is easier to obtain. This document will set out the basic criteria for making a more scientific decision and reasons behind them.
Factors to consider when choosing thread type:
- end use of garment:- what performance is required
- fabric type to be used and 'handle' required
- range of shades available in chosen thread range
- availability of thread type in production location
Characteristics of each thread type:
Use viscose rayon for:
- superior lustre, sheen and handle
- delicate and intimate fabrics - esp.next to the skin
- high density woven fabrics - avoids looping
Use trilobal polyester for:
- fastness to bleach and special treatments
- superior abrasion resistance - esp. sportwear
- for course fabrics & leather - better resistance to heat
Dominance of Rayon: twenty years ago nearly all the world used rayon - this filament came mainly from the Akzoenka company in Germany and there was little other choice if first quality results were required - but it was expensive; nowadays cheaper (weaker) rayon filaments are now available - mainly from Korea and China - but cheap rayon tends to be less consistent and too weak for many types of fabric
Improvement in Polyester: the first polyesters used for embroidery were a poor comparison to rayon in terms of lustre and performance but over the past 10 years the invention of trilobal (triangular cross-section) and subsequent improvements have come much closer in terms of look and performance. However there is one area where polyester is inferior to rayon; the propensity to form loop faults; this can be a major cause of rejection and rayon - used in the same circumstances - does not loop at all. Looping can be reduced by good digitising and by avoiding certain types of fabric such as tightly woven nylons where use of trilobal may cause an unacceptable level of looping.
Long term trends: polyester is winning the battle due to superiority over rayon in terms of fastness, strength and the continuous development of improved (smart-fibre) polymer technology - in the future we can expect almost no difference between the performance of the two thread types but at present there are certain circumstances which restrict the use to only one type of thread. Generally speaking - for normal fabrics and low-stress embroidery - it makes little difference which thread type is used
Market development: some embroidery markets - especially emerging ones - tend to favour use of polyester threads due to ease of dyeing and the poor quality of available rayon filament; in today’s fast changing sourcing environment it is critical to choose a thread supplier who can stock thread close to where the embroidery is conducted.
Colour range: polyester and rayon use different dyeing chemistry; as a result some colours in one type of thread - rayon for example - may not be achieved in polyester; this only applies to bright or heavily saturated colours; as a general guide try to choose colours from [any] rayon shadecard when requesting rayon shades and choose from [any] polyester card when requesting polyester shade - that way the supplier knows that they can in all probability acheive the desired colour you want.
Other factors: choosing the best embroidery thread certainly improves the chances of obtaining the best quality embroidery standards but does not guarantee it; good machine maintenance, use of supporting materials such as interlinings and professional digitising and your choice of embroidery contractor are the other main factors in maximising embroidered quality
Fitness for purpose: first consider the use of which the garment may be put; end-use, washing conditions and exposure to chemicals - ultimately your choice may be restricted to one or the other type because - for instance - you require the garment to be bleached
Availability in embroidery locations: next consider the lead times from various thread suppliers in the desired location; it may be easier to allow a polyester in a particular market if that is easier to obtain - provided it does not conflict with fitness for purpose - but you might need to make ca compromise over your choice of some shades - especially bright or saturated ones
Colour range: try to select colours from a shadecard of the same substrate; one supplier can normally match any shade as long as it is in the same fibre type - remember that you can expect significantly better service if you choose a shade from the supplier's own shadecard
Other factors: choose an embroidery partner rather than an embroidery thread; select a company who can provide support in all the elements of embroidery excellence to ensure your excellent designs get translated into excellent embroideries - time after time