If you choose to paint without primer, it can lead to a variety of issues. Without an underlying layer of primer, the top coat will not be able to adhere properly and will fail much sooner than if you had used a primer. The paint may also chip more easily due to insufficient bonding with the wall or surface you are painting on. Additionally, any imperfections in the walls like cracks or holes won’t be filled in and sealed away by the primer which means they will still show through your finish coat. Painting without primer also causes problems when trying to switch up colors as dark colors especially tend to bleed through lighter ones; some discoloration could occur even after multiple layers of paint have been applied overtop. In conclusion, while it is possible to complete a successful painting project without using a primer beforehand, it is best practice for long-lasting results!