Are color contact prints/proof sheets from the lab useful?

I use mostly 35mm and 6x6, but also occasionally shoot 4x5.
I have never asked for contact prints or proof sheets from the local lab. Do you often do this?

The guy at the lab told me about some people who lost their negatives and who managed to make some decent enlargements (within limits) from contact proof sheets. What kind of resolution/sharpness would you expect from, say , trying to scan and print 4x6 prints from a proof sheet? Are the proofs sharp and detailed?

Presumably you are talking about an analog contact sheet. You could scan the contact with plenty of resolution for a 4x6, not sure about going much larger than that, especially for 35mm. Paper doesn't have nearly as much resolution as film, so some detail would be lost.
As usual, the larger the negative is, the fewer problems you'd have preserving the available detail.

I used to make B&W contact sheets, but don't routinely bother now, as I can, at least for my purposes, judge from the indexed negatives what I need to scan or print.
I can understand lost pictures being "rescued" from contact sheets, but the quality is only going to be as good as the (tiny) print image. Remember also that a contact sheet made the analog way (i.e. not scanned) is going to be made with an "average" print exposure for the whole film, no corrections for contrast or density.

hi trondsi

believe it or not, i have lost negatives and have made beautiful prints using a contact sheet from 30 years ago !
they are electronic, but i am confident if i had to, i would be able to make a copy image from the contact frame using film ...
contact prints ARE useful. but i don't get work printed at a lab too often, and i don't bother printing them myself anymore.
i should though! they are a good way to separate the good from bad ( if they are the same density ) my "problem" tends to be
that sometimes not all my exposures are the same density so it would be difficult for me to make 1 contact sheet so i might have to
make 2, 1 for more dense negatives, one for thinner negatives.
i do cheat though ... i often times make an electronic negative still not as much fun as watching the pape turn from white to print...

good luck!
john

Thanks everyone!
Yes, the local lab makes them the analog way. I think I'll ask for contact proofs next time I bring in some 120 negative film for development.