Of course you can add tylose to already made fondant. I do it all the time. If you dont want to its ok itll just take longer for your loops to dry. but i strongly recommend to add tylose to the fondant paste mixture of fondant and water that you will need to use to "glue" the loops together. This will make ur bow SO much sturdier and you wont be afraid of handling it. I made this red bow for a cousin of mine for her cake and she still has it from almost a year ago!!