July 23, 2019

Sewing -- thread

Don't use crummy thread. I use 100 percent polyester for everything. I buy only Gutermann -- and it is readily available.

The cotton coated polyester stuff you see in the various local sewing shops serves no purpose for the home sewer. Cotton coated polyester was developed to be used in high speed commercial machines that are sewing so fast and continuously that the needle gets hot and melts the polyester when the machine stops briefly. This is hardly what you need for home sewing and my impression is that it must be "surplus" from the commercial market.

Cones versus spools

If you are new to the sewing world, you have probably only ever seen spools of thread. They sit on a rod on top of your machine and spin around as thread comes off. Cones are entirely different. They must not spin and should sit on the table next to your machine. Thread goes straight up and off of then and you rig up a "tree" (I used a bent coathanger) with an eye where the thread makes the turn to head towards the machine. If you buy heavy duty thread, it will come on a cone. If you treat it like a spool the thread will get twisted and you won't be happy.

Tex and Mara and Tera

Tex ratings were developed in an attempt to standardize thread nomenclature, but certain segments of the sewing world cling to other systems. The idea is that the Tex number is the weight in grams of 1000 meters of thread. So bigger numbers indicate a heavier duty thread. This is the opposite of the "wt" system where finer threads have bigger numbers. Most of what I have is either Tex 30 or 40, which is a medium weight thread. Note that comparing a cotton thread to a polyester thread of the same Tex value is not straightforward.

Mara and Tera seem to be Gutermann specific terms or trade names. I have a bit of what is called "Mara 100" and it is Tex 30. I have a lot of "Mara 70" and it is Tex 40. Mara 50 is even stouter (it is Tex 60), but I don't have any of that.

I do have one cone of "Tera 80" which is Tex 35.
I have another cone of "Tera 60" which is Tex 50.
See below on Tera 40, which is Tex 75.

For heavy duty use I would call Tera 60 the best choice. Even though it is thinner than my Mara 70, it is probably stronger. Any machine should handle it, which is not the case with Tera 40.

I now have Tera 40 in hand, and can use that for really hard use cases, but see my notes below.

Here is some information from Gutermann:

Most fabric stores carry Gutermann Sew All which is a Mara thread and the most common size is Tex 30. Mara is a MicroCore Spun Polyester thread and Tex 30 is the most popular Tex size sold in the home-sewing market.

Mara is a MicroCore, Spun Polyester thread, made in many Tex sizes and is typically used for construction and decorative stitching on apparel, leather and accessories. The appearance of Mara is a low luster, matte finish with a 'natural' look of silk thread. The thinner Tex sizes are used for garment construction and the thicker Tex sizes are good for buttonholes, decorative topstitching (denim) and leather accent stitching on handbags, wallets, belts, etc.

Tera is a Continuous Filament polyester thread that is made in a different technique and is known for it silky, shiny surface, and strong resistance to abrasion. Tera is slightly stronger than Mara (pound for pound) in like Tex sizes and Tera is normally used for upholstery, leather stitching, outdoor fabrics (awnings, marine upholstery, umbrellas etc.

Both threads are made of 100% polyester, so they both have similar resistance to UV and chlorine, but normally Tera is more commonly used outside or in high sunlight exposure.

Sometimes, people use names that are confusing and normally, our Gutermann customers use the threads 'proper name as shown on the cone or spool. Some retailers use descriptions of the thread that do not match the thread name and this is a little misleading. The Sew All thread you see in Joanne stores or other retail fabric shops is Mara 100 (Tex 30). The heavy topstitch or heavy duty Mara is normally Mara 30 (Tex 100), typically used for denim. This is also called jeans topstitch thread. Tera is found in some retail stores under the name "Upholstery thread) and this is Tera 40 (Tex 75).

Most Distributors use the actual thread name like Mara or Tera and use the corresponding Tex size to describe the weight or thickness of the thread. For hammocks, backpacks or similar applications, the Tera 40 is my recommendation. It is available in most of our Distributors and the color range is fairly wide. The thinner Tera threads are great for ripstop nylon as this fabric has a tendency to pucker - so the thinner the thread, the smaller the needle and the least amount of pucker. In that case, Tera 80 (Tex 35) is perfect. This thread is not as widely distributed as Tera 40, but should be carried by more Distributors in the future.

Tera 40

This is ridiculously strong thread and you probably do not need or want it. I bought it on a big 1300 meter cone, which should last me forever. See the photo at the top of this page. After getting it and puzzling over needle sizes, I read some people saying that it very well might not work on a home machine. My faithful Singer 401A would not handle it. The hook just would not grab the thread, and the usual business of bringing up the thread from the bobbin would not work. So I moved on. Next I tried my faitful Elna 62C, using a 90/14 needle. This has no problem at all. I thought I might have to adjust bobbin tension, but even that has not been needed. It threaded like always and immediately sewed like a dream. But you have been warned. If you have a slick modern machine, who knows. If in doubt, just stick with Tera 60. I thought I might have had to go all the way to a 16 needle, but the 90/14 seems to be working just fine.

Other systems

You may also hear about "weight" and "denier".

Weight is the inverse of Tex. W = 1000 / Tex or Tex = 1000 / w. So bigger numbers indicate a finer thread. The defining idea is that "weight" is the number of kilometers of thread required to weigh 1 kilogram.

Denier is the weight in grams of 9000 meters of thread. D = 9 * tex and Tex = D / 9. Like Tex, bigger numbers indicate a stouter thread.

Needle sizes for various threads

I was told to pick the thread for the project, then the needle for the thread. The crucial thing is that the thread lays in the groove in the needle. Here is someone elses table from Hammock Forums: 
Mara;	Tex;	Needle	
220;	13;	
120;	25;	
100;	30;	"10-12"	(sew-all)
70;	40;	"14-16"	
30;	100;	

TERA; TEX; Needle	
80;	35;	"10-14"	
60;	50;	"14-16"	
40;	75;	"16-18"	
30;	100;	
20;	150;	
15;	200;	
10;	290;	
8;	375;

Where to buy it

All of the usual DIY outdoor gear places have Mara and Tera. Here is another place:
Have any comments? Questions? Drop me a line!

Tom's home page / tom@mmto.org