Hi all! My husband ordered some of the fretless finger guides (link below) from Ebay, and normally I am skeptical of things like this, but I was impressed that my husband, 46, who has had an interest in learning to play violin was able to play a song within an hour of receiving the fretless guides in the mail and the instruction book. Whats more, after playing the song several times with the guide, he then tried the song on a violin without the guide, and did a reasonably good job with intonation and correct finger placement playing the same song. The fretless guide he got was made of acrylic, like a window cling, with colour coded, notated placements, which match the colour coded printed standard music notation in the book, and it wraps around the neck and is held by static, no adhesive or glue and doesn't harm the finish of the fingerboard. This company had 4/4, 3/4, 1/2 size guides but unfortunately no smaller sizes.

I have played for over 30 some odd years, classically trained, and I am usually skeptical of a lot of the merchandise on the internet, especially sight unseen buying, and I was afraid it might affect the sound quality, but this impressed me. My husband is not only associating the notes on the violin with music notation, but he is obviously learning correct finger/muscle memory, pitch memory and intonation.  

Now if we could find a 1/4 for my son (:  

 http://www.fretlessfingerguides.com/