You can contact a local cabinet shop that does Corian/Solid Surface counters. They usually have scrap pieces left over that they can make a threshold with.

That's what we did in the past (and are getting ready to do again) for a shower seat.

Or try a granite/stone yard. We got our 2 stone thresholds (shower stall and main room door) for $50 - finished and cut to order. If I recall, the not as nice ones at Lowes/HD were about $20 each anyway. So I got nicer stone that matched beautifully.

I just went to a local granite yard where they had a remnant that was a good match to our counter tops. They gave me the remnant for free and charged something like 40.00 to fabricate it.

You need to make sure that whatever you use is strong enough and will never crack. I seriously doubt those travertine transitions sold at the big box stores would be strong enough. Not to mention that they are butt ugly. We have one in the doorway of our powder room and I pray for the day we can have it replaced with something nicer.

Thanks for the advice. My contractor wants to do this tomorrow - can the threshold be done after everything else is complete? I don't have time to visit stone yards before the weekend to try to find something that works with the floor.

That said, the Carrara is gray (light) and it might not be bad with the dark gray floor tiles. We don't have any stone counter to match it to unfortunately (counter is walnut).

My fabricator was able to turn around in 1 day. That said, it there nothing else the the contractor can do until next week? Paint maybe? Seems to me that he should have made it clear to you that you need those pieces so if this puts him off schedule, it's his problem.

However, I do think you could find a "muddy" piece and use that - I don't think it's a huge deal (but I will say I look at mine a lot and smile at how well they match with the color on the floor/shower tile :) )

Local tile shops may sell stone windowsills or curbs that may work. We got ours at a place called Tapcu in Atlanta. We used white marble ones for the shelves in the subway tile tubs and walnut travertine for boys showers (they have walnut travertine porcelain tile walls). We used ivory travertine for our master shower. They were very reasonably priced and very high quality (2 cm thick and very sturdy).

They were prefabricated, so just had to be cut to size.

A couple of quick thoughts.

1. Unless the contractor wants to install something such as a shower door (that requires making holes in the curb) tomorrow, the installation of the curb/threshold certainly can wait. It just gets glued in place and then caulked. So unless tomorrow is the last day, it shouldn't throw the work flow off.

2. Like KathyNY76, our fabricator also was able to turn around the work in 1 day. That was for a 65" curb/threshold and a 45" long top for the pony wall with very simple edges. (Our tile guy did the installation. He asked that the fabricator make the curb two inches longer; he cut it to the final size).

3. It may be a matter of semantics and/or regional differences, but here in New England it's the fabricators who have the remnants and not the stone yards. Still requires a bit of looking, though. You should be able to find a couple of options that coordinate with your tile and the look and feel of the room.