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Go to the tools panel of Affinity Photo and add some text, either artistic text or frame text, the method works for both. If you try and use the liquify persona (top left) the text is in the wrong format. If you want to proceed then you will have to rasterize the text and that means it is no longer live. Instead go to the layer menu and new live filter layer and distort and liquify. All the same features and panels etc that are in the persona, are now also in this live filter layer. So you can change the mesh as well as apply brushes such as push forward, turbalance, twirl, clone etc as well as change the brush size, hardness etc. So apply a brush such as twirl to warp the text, hover over the area you want to warp and click with the mouse and the design will then warp based on the current settings. Once you are finished with that, click done in the top left. You will see now that the effect has been added just below the layer. You can move the effect layers around, if you decide you want to warp the entire image and layers below, simply drag the entry above all the other layers. To change the effect, go to the entry and double click it and it will again display the mesh and all the brushes and you can reset, tweak etc. If you want to change the text, it is quite hard with the effect added but you can always deselect the check box in the layers panel for the effect and you will see the letters / words etc in an easier to edit form, now change the words. Remember to put the effect back on afterwards. You can also duplicate (hold down the alt / option key on your keyboard) and create multiple layers and each one of those can have different warping applied.