Airline restrictions on laundry soap?

Jennie, There are no limits on powder. You can take as much as you want. We put our Forever New in 4oz plastic bottles, 12oz of it and supplemented it with hotel liquid shower soap. The liquid soap that Ibis hotels provide is excellent for laundry.

Thanks for the info!

We actually do laundry when we are in France and Italy. It is always an adventure to find a self service laundry. I don't use any special product. I put a cup of Tide in two baggies, use the twist tie and then put several bags in a larger ziplock bag. I also include several dryer sheets. I have never had any problems with the soap powder in either a carry-on suitcase or in checked luggage. We have talked to many interesting people in the laundromats. I am smiling now remembering the 90 year old man in Italy who kept squeezing my arm as I "talked" to him and he kept saying "Bella, Bella!". My husband reminded me that I helped an Australian newlywed fold clothes while his pregnant wife was back in the hotel. We also enjoyed talking to another Australian couple in a Paris laundry and having dinner with them. Doing laundry can be a fun way to meet other travellers sharing the same chore.

Do they sell small packages of detergent at laundromats like they do here in the U.S.?

In France individual portions of laundry detergent are available at the laundromats. However, all that I've used is heavily perfumed. If your clothes are just sweaty, you can clean your clothes with 1/2 or 1/4 the amount of detergent in each package. I plan to take some laundry detergent I found at my local grocery store. It is in capsule form like some of the dishwasher detergents. One capsule is recommended for hand washing and two for laundromat use. I will carry the number of capsules I expect to use at laundromats during my trip. I use shampoo for hand washing. One problem I ran into a few years ago was that the powdered laundry detergent I took from home didn't dissolve properly in the French machines. One solution would be to wait until you arrive in Europe then visit a store and buy a quantity of laundry soap. If you are traveling with others, the soap in the package could be shared among yourselves.

I realize the question is about packing detergent rather than the use of it. But I thought I'd mention that most machines in various European countries are quite a bit smaller than American models and so don't hold as much. So you'd need to use much less washing powder. I have seen Americans who apparently didn't realize this overfill the washing machines and suds spill out all over the floor.

New philosophy - - pack light, then load up your luggage with all kinds of stuff that's readily available where you're going?

I'm taking all my food with me on my next trip because the food over there smells funny.

When planning on hand washing in hotel sink,, it only makes sense to bring some soap from home, I personally do not care to waste my vacation time or money on looking for laundry soap.. for a week or two one can easily take a small container of the Forever New( love that stuff, it works great and rinces out easily) and still have lots left over.. or throw a small ziplock bag of your regular washing powder in your suitcase,it takes no extra room and will last for 2 weeks if used for hand washing.
I also pack a few blow up balloons( yes the cheap ones you get for kids parties etc) as you can hang a top on a hanger, the inflated balloons in the chest to hold the sides apart, and shirt is dry next day.. Then throw away balloons. Again, no extra room taken in suitcase, and many of us have junk drawers at home with a few balloons somewhere in the bottom!

Purex makes laundry sheets. I pack a few on every trip. Also doubles as fabric softerener sheet. Had no trouble using them in Europe.

I also pack laundry sheets (from REI), they come in 50 sheets - not much bigger than a book of matches - don't need to go through TSA as liquids, and weigh nothing. One sheet is plenty for washing a couple things in the sink, three of four for a full load in a machine. For powder detergent, a ziplock baggie in your luggage should work. It doesn't need to be taken out for inspection. Don't leave too much extra air in the bag, the air expands as your plane gains altitude and could open or break the baggie.