There are a few reasons why your lines might disappear or simply not appear (even though your stylus is charged and connected) once you’ve drawn them.
If your lines are vanishing:
1. Check that your opacity is above 0% for your tool. You can find the opacity slider on the inner ring of your tool wheel, listed as a circle with one side filled in. 0% means invisible, 100% means as solid as your tool gets.
2. If you’re using a pressure sensitive stylus, check that your pressure settings (found in Settings > Stylus) are set low enough to allow you to see your most delicate pressure. Of course, you can customize this to your preference.
3. If you’re drawing with the Filled Stroke tool, check the tool's smoothing. For most tools, smoothing simply turns your strokes into straight lines. However, the Filled Stroke tool fills the positive space between your starting point and ending point, so 100% smoothing minimizes your shapes to short lines or points. If you’re starting and ending near the same spot, it’ll seem like your shapes just disappear, so make sure your smoothing is set at the right level.
4. Check that you are drawing on a visible layer. Automatic layering separates your strokes according to tool type, so if you’ve turned off visibility for a tool, it can be confusing when picking that tool up again. Helpfully, if the layer for your current tool is turned off, a popup will appear to warn you you’re drawing on an invisible layer, with the option to make it visible.
5. If you are using a Mask, check that you are masking on the right layer. The Masks only work on the currently active layer, so if it appears they aren’t affecting your strokes of choice, you might be on a different layer. Remember to check that your opacity is above 0% for your Mask, too.
6. There is an occasional bug with a first generation Apple Pencil that the stylus refuses to connect with your iPad unless it is charged separately first. Plug it into your laptop or lightning adapter using the tiny female adapter that comes in the Apple Pencil packaging (it's easy to miss). Then pair with your iPad.
If none of these work, please send us a message via Help > Ask Us Anything in the app.