Hi Craig,
Welcome to Affinity Forums :)
Make sure the layer type you are working with is a Pixel layer. You can identify the type of layer looking at the label between parenthesis after layer's name in the Layers panel. If it's an (Image) layer, right-click on it and select Rasterise.... You should now be able to edit it with the healing tools.
An Image layer is an object layer type - you can transform it "globally" (scale, rotate, skew etc) but you can't edit it at a pixel level. A Pixel layer is a "container" for performing pixel based operations.
Hi pomme27,
Go to menu Window ▸ Separated Mode. You can now have each document in its own window and place them side by side.
You have to open at least one image for the command Window ▸ Separated Mode become available.
Hello fred reichardt,
Welcome to Affinity Forums :)
You have to enable Separated Mode as i have described above then open both images (let's call them A and B ), go to image A, select the Clone Tool, press and hold ⌥ (option/alt) and click over the area you want to clone to set the source area. Then, still on the same image go to context toolbar and click on the Set Global Source button. Now go to image B, select the Clone Tool, go to the context toolbar, click on the Current Layer dropdown and change it to Global. Place the cursor over the target area and it should paint with the data from the image A.
