protocol on letters of recommendation

Hi OPM-ers
It’s been a while since I’ve had time to visit and read what everyone has been up to - so I hope everyone is doing well. I have a quick questions and could really use some help. I am applying for a month long program offered by UMass Medical and needed 3 letters of recommendation. I asked 3 of my professors and they were kind enough to take the time out of their busy schedule to write up the letters and sent them off relatively quickly. (I have never had to request letteres of recommendation, so I am a virgin at this.) I was told that I need to write thank you letters to them, and it should be done immediately. So now that I have these letters to write, what kind of paper should I use? should I write a letter or a card (professional cardstock). What should I include on the note other than “thank you for writing a letter for me”. No those are not the exact words I would use but you get the jist.
Well I have to go. Thank you so much for your help in advance.

I just bought a box of thank-you cards at Wal-Mart and wrote a short note to each person. In the note, I of course thanked them for writing the letter, and I also personalized it a little bit depending on the relationship that I had with that person. So for the one for my boss, I not only thanked her for writing the letter, but also told her how much I had enjoyed working with her these past couple of years. For my PI, I said that I had learned a lot of chemistry from him and that I appreciated him being such a great mentor. And so on. Basically whatever that special something is about that person that made you decide to ask them to write you the letter is what you can comment about. It’s a nice way to let the person know that they mean something to you outside of being a means to getting a LOR. Hope this helps.

Nice looking, simple, clean Thank You notes will be perfect. You want them to look professional, but do not go overboard on expense. Simply hand write a thank you note - does not have to be much nor lenghty nor sycophantic.