Kat here!
Hilo de algodón nylon polyester rayon etc.
Just a few words about thread – things that seem obvious until you really start digging in for more information.
Our thread section has many styles and materials represented in the selection, so a few words of explanation might help if you're not up on the technology.
Polyester vs rayon or nylon or cotton or silk or...
Polyester thread is slightly stronger, and stiffer than rayon. It is bleach and cleaner resistant. Polyester is the better choice for heavy use clothing or anything you may wish to sanitize with bleach. It has a bit of "give" to it, making it ideal for stretch fabrics and knits. Polyester thread is considered the thread of choice for the average home sewist.
Rayon thread is another man-made fiber, which is more supple than polyester, allows better shaping, and drapes better. Rayon is the serious designer’s choice for best appearance but tends to fade faster and shrink.
100% Cotton Thread is good for high-speed sewing -- it doesn't melt. Cotton thread has excellent sewabllity with little kinking or skip-stitching and it’s rarely affected by hot needles. Cotton thread does not stretch and tends to break where seams are under stress, so a stretch stitch is recommended.
All purpose thread is a Polyester core, cotton wrap thread. It is a thread that keeps the authentic look and feel of cotton while maintaining the strength of polyester –- due to the hybrid polyester core!
Silk thread is very smooth so it travels through even the lightest most delicate fabrics without leaving a mark, as well as being very strong. It's sheen makes it a good choice for a large variety of sewing projects including embroidery and decorative stitching. Silk thread is used for very fine invisible stitching in high-quality suits, for example. It is also a first choice in many embroidery applications.
Metallic Threads are usually a synthetic core with a metallic (or metallic looking) outer coating. These threads require a lower tension setting and probably a lower speed. In addition, use a larger needle to ensure that the stitch hole is not resisting the thread movement.