Russ - your are right - I neglected to count France for some reason - but I would try to get a cheap Thalys ticket Paris to Amsterdam, available from 35 euros in 2nd class (yes if I were buying tickets I myself would probably do 2nd class but the railpass only comes in first class and IMO it would stack up fairly well against 2nd class regular fares so why not enjoy the significant benefits IME of first class for not much more if any.

And Mimar is right in that some trains in France and Italy - most trains a tourist will take demand seat reservations - the Thalys train is about the most expensive in Europe for passholders, charging an obscene IMO $40 or so supplement even for 2nd class travel with a pass - so the OP could get a cheaper Paris to Amsterdam ticket and not use the pass and then get a 6-day Eurail Select 5 Country Pass and save quite a bit of money.

thanks Russ for pointing out my miscue!

And again I was glad I had some first class seats on that train to Fuessen when school kids mobbed aboard - though it was not a dedicated car I was in a dedicated section where the kids standing all over the 2nd class area dared not to enter. And the schoolkids is not an anomaly IME on regional trains in Germany that often IME double as school buses as students seem to travel often from nearby cities to a larger city for upper level schools.

try www.thalys.com for deep discounted Thalys tickets to Amsterdam

the Global Pass mentioned above is good for folks traveling many days on trains in a short period but the OP IMO is better off considering the Flexipasses that are good for two months and give you a certain number of unlimited train travel days midnight to midnight. OP does not indicate they will be using the train most days and they are going for 45 days with just several train rides indicated so the flexipass would be better than Global Pass as for 45 days they would have to buy a 2-month Global Pass at way way too much money - just use the Eurail Select Saverpass for how many actual travel days you need - six days as you can buy the Paris to Amsterdam Thalys ticket cheaper than what the supplement is if you used the railpass for that (7th) day.

You need to buy seat reservations for the French and Italian trains. These are not always available at the last minute for popular routes. (There is a limited number of seats for passholders.) So a pass does not offer the total flexibility PalenQ touts.>

In Italy I have never ever not been able to get any mandated seat reservation I wanted on any train - even right up until the train. Of course I have a first class pass so seats are much more available in first class as the railpass OP would have would be.

In France there is a problem with TGVs from Paris to the south of France but on most other routes no.

So for the OP I stand by what I said as OP is not taking any route that they cannot easily book en route.