I love the idea as I always have more rhubarb than I can use and I made these using it fresh cut from the year. The "raisins" were made yesterday, I put the tray in a 150 degree oven for between 10-11 hrs and none of my pieces were over 1/2 an inch in size. I used Splenda for the sugar and that seemed to work fine but sugar would look nicer I think. I put them in a jar to sit overnight and found that they were a touch sticky this morning. I guess they weren't as dry as I had thought. This is one of those recipes that you'll need to try and see what works best for you taking into consideration the moisture content of the rhubarb, if the day hot and dry or damp and rainy (damp and rainy for me yesterday), and such. This morning I used them to make Oatmeal Lace Cookies With Dried Tart Cherries using the rhubarb in place of the cherries. Very yummy!