What are the Pros of the ChestRest?
There are several points to mention:
1-no pain in the neck or shoulder because you will knead the ChestRest to your body. Eventually it will be a very supporting and comfortable rest and the violin will feel as an extension of your body.
2-playing the violin is easier because you do not have to worry about holding the violin. It allows your fingers and your mind to play and only to play.
3-no need for a chin rest. Without the chin rest you are in direct contact with the violin and the violin sounds better. I found it an amazing experience when I removed the chin rest and began playing. I had no idea that my violin had that sound. So much better. Also you will feel the sound vibrations going through your head and body, you hear and feel your music at the same time.
4-MentalRest when you screw up your ChestRest. Just print a new one and try to avoid the previous errors.

What are the Cons?
1-it takes time and effort to mould the ChestRest to your specific body posture. I need about a week to get it really fine tuned to my body. A squeeze here, a squeeze there, a notch here, a notch there. Well, you get the idea. Be patient and do not rush. Let the ChestRest tell you where and how it needs to be squeezed and bend.
2-The present design is a template, an 'one size fits all' design. For most people it will fit but maybe not for you. Especially if you have a very long neck, a funny collarbone or some other specific body features. If that is the case then go to your Local Makers 3D shop and redesign the trouble spots to fit your body. It is a free design, tinker, just tinker.

Can I fold the ChestRest?

No, in the present design the ChestRest will be one solid piece.

What is the target group for the ChestRest?

In principle everybody who plays the violin. Especially those that are experiencing neck, shoulder or other pains when playing, could benefit using a ChestRest. Also players who find it difficult to hold the violin with the standard shoulder rest. Just print one and try.
A special word for the professional violin players.
Professional players are especially invited to try the ChestRest since they have to practice a lot and are more prone to neck, shoulder or other issues then recreational players.

Is there a ChestRest for a 1/4; 1/2; 3/4 violin or viola?

No, the present design is only for a 4/4 violin. Maybe you can scale down or scale up the present design to fit other sizes. Just try.

Is the ChestRest as safe as a normal shoulder rest?

Actually safer then a normal shoulder rest. When assembled correctly the ChestRest will securely fixate your violin and your violin is always, in a natural manner, in secure contact with your body.

What effect has the ChestRest when playing?
The ChestRest is and feels much more stable than a normal shoulder rest. These features translate into improved playing. Your playing skills will improve dramatically. Something I did not expect at all. A huge bonus.

What about Violin Pure?
Playing the violin without any attachments in a relaxed manner is the prime feature of the ChestRest. The violin is a dynamic instrument when played and the ChestRest accommodates this perfectly. Playing Violin Pure feels so natural, safe and relaxed; this is the way a violin should be played. The violin rests on the silicon strip. The silicon behaves like a second skin, is non-slipping, is easily cleaned with water, does not impede the sound and does not damage the lacquer. We tried different options like a silicon cushion, one strip etc.; looks great but playing becomes more static. It turned out that foam rubber enclosed between two sheets of silicon yielded the best result. It may look a little bit awkward, but this configuration allows for lateral movement and adaptation to your position, all the while being very supportive. The present configuration turned out to be the best so far.

What about playing the CR with a shoulder rest, what’s the point?
Playing the ChestRest with the shoulder rest mounted onto it allows also for relaxed playing, more so than with only a shoulder rest. The cons of a shoulder rest are that one needs to press onto the violin otherwise it slips and because of this playing becomes more static, more rigid. With the shoulder rest mounted onto the violin you can play more relaxed and a bit less static then with only the shoulder rest. Just try.

What about the name ChestRest?
Well, the name had to be catchy, short and apparent; which I could not produce. Luckily Jean Castelein came up with the name ChestRest. She also took the pictures in the Buy/DIY section and sewed the soft Velcro onto the silicon padding. Thanks Jean!

The big question is of course: Would you use the ChestRest to play a Stradivarius? Yes!

Why is the design free of copyright?

The reasons to release the ChestRest under the Creative Commons Zero license are very simple.
I like to play the violin but because of the increasing neck and shoulder pains with the normal shoulder rest I nearly quite. With the ChestRest the sheer joy of playing the violin is back.
Creativity is one of the most important aspect of the human experience. The technology is ready, now let's share the fruits.
Sharing creativity, sharing innovations, sharing knowledge, sharing experiences; this I find most uplifting.

To the extent possible under law, Marc Hagens has waived all copyright and related or neighboring rights to the ChestRest. This work is published from:  the Netherlands.