PicMonkey layers are stratified graphic design elements like text and images that sit on top of a canvas. You can order and reorder them so that they overlap just how you want them.
Whether you’re using a template or designing something from scratch, you can keep track of your layers by using the Layers palette.
Effects and textures can only be applied to the background layer of an image. That means if you want to apply an effect to an image that you add to your canvas, you first have to flatten the entire design to the background, or apply the effect to the image before you add it to your canvas.
To flatten the layers in your canvas, click the Flatten image button (the two stacked squares icon) in the bottom left corner of the Layers palette. Note that this will flatten all the layers in your canvas to the background.