Are there guitar strings made ALL from nylon?

Not sure what you're talking about here actually. Classical concert guitarists of the highest calibre (we're talking worlds best) use the type of "mixed sets" you're referring to here. Naturally they use expensive sets.

You have two options available today. The common sets which have plain nylon treble strings and bass strings which are made of fine plastic/nylon threads - usually wound with silver plated copper wire or some times bronze wire.

It is the quality of the wound material in the bass strings as well as the tension of the treble strings that determine the quality of these strings. Professionals tend to use treble strings with high tension as these tend to "sit" better with the bass strings. Also, you will need to change the basses quite frequently. They lose tension and may sound dull pretty fast.

All nylon bass strings would not produce enough sound at all. There's a reason why they're wound... The same goes for metal strings on electric or steel string acoustic guitars - the basses are always wound.

The second type of strings for classical guitars are the traditional strings of old: gut strings for the treble and bass strings where the core is silk thread which is then wound with gut. You may still find these for example here:

http://elderly.com/accessories/items/AGNS.htm

I suspect that only the very best guitars (like really, really expensive ones), will benefit from the more expensive sets of nylon/gut strings.

When I used to work with classical guitar repair and sales, we had many pros in our shop. From what I can reacll, they all played standard (although top-quality) nylon wound sets, hard or semi hard tension on extremely expensive instruments - $5000 and up into the tens of thousands region.

YOU have offered no specifics. But I will attempt to. SAVAREZ makes an all wound Nylon classical guitar set. All the strings are wound from the 6th to the first string.

Lester G is right. Lamb intestines( comparable with all stringed gadgets of the previous). some Violin strings are nevertheless made with gut. ( additionally sausages and organic casing frankfruters).