Now that you have figured out the correct weather to spray primer in, you will have to set up an area to paint in. This can be a messy technique to prime with, so always ensure that you place your models in a cardboard box when you are applying paint, lining them up on a piece of wood or cardboard with blue tack prior, so that they are well spaced and unable to move as you are applying primer. When spraying on primer with your rattle can, always hold it about 15-20cm away from your models, applying it in short bursts whilst moving so that you can avoid obscuring any detailing with too thick paint. 

Spray-on primers are available to you as model-specific paints from brands such as the Army Painter or Vallejo. Since these primers are designed for use with minis, the paint has a slower and smoother flow speed out of the can, allowing you to apply primer in thinner layers that will not obscure any small details on your character. You can also use any primer brands found in hardware shops. These brands are often cheaper than the mini-specific paints, but often have a faster flow of paint that can cause it to obscure your wargaming miniatures' details and often take a longer time to dry and cure. 

Airbrush priming 

If you want to work around the weather complications of spray priming with rattle cans, you can use an airbrush. Using an airbrush is more difficult than using a rattlecan, so it is often more popular with more experienced model and wargaming painters, but it can also give you the smoothest finish out of all of the priming methods. 

Brush priming will always take longer than airbrushing or spraying and will always mean that you can only create minis in small batches. However, you will always be able to ensure that the end product is consistent across all of your models. Taking the time to ensure that your models are primed correctly, instead of batch priming with a rattle can, means that you can avoid any spray priming horror stories. If you spray prime one batch of minis incorrectly, you will have to strip all of them, but if you make a mistake when brush-on priming, there will be minimal damage and only one character to strip.

You can buy many brush-on primers, like those from The Army Painter or Coat d'Arms, which can often be used straight from the tube without any thinning, but you can also use gesso as a cheaper option, which is available to buy from almost all art shops. When brush priming, use a larger brush than any you would use for regular painting or base coating, such as ABCbrushes Spearhead Red Sable round or Tri-Grip Wave Synthetic brush in a size 0. Use this to apply the paint all over your model, painting in thin layers and always waiting for each layer to dry before you apply another one on top, so you can avoid creating brush marks in any semi-dry paint. Having patience with this technique is key, if you rush to paint over your layers, you can potentially ruin your entire paint job. Using high-quality brushes will also massively help you to achieve a smooth, even priming coat; the fine bristles found in brushes made from sable and soft synthetic hair are best suited. 

Try to stay consistent with the thickness of your paint across the entire model and avoid any bubble formation in your brush-on priming layers. Bubbles can create recesses in the paint that will show through to the final layers of your designs. Stab them with the end of your paintbrush or tap the model on your desk as they show. 

• White primer - White primer is perfect for when you need to paint bright, light colours, like glowing elements, blonde hair or light clothing. If you are planning to paint any models with a vibrant colour scheme, you should start with a white primer. It also gives you a lot more control over the placement of your shadows, but this can also mean that you will have to work harder to paint these accurately, making white primer more popular with experienced wargaming painters.
  
  
• Grey primer - Using grey as a primer gives you a more neutral starting point, essentially combining the benefits of both black and white primer. You can keep areas dark for shadows, while also ensuring that vibrant colours are still visible, enabling you to work on painting either up or down in values easily. Obviously, grey will not be able to ensure these two elements to the same capacity as black or white, but it provides a more neutral option.
  
  
• Zenithal priming - Zenithal priming is a more advanced method of priming that involves laying down light and shadow in much more detail than any one colour primer. This method involves priming with two different colours, emulating shadows and light from a specific direction. You start by priming in your darkest colour before using a spry-on primer to apply with your lightest colour at a 45 degree angle, leaving recesses that would be naturally darker in shadow. 

• Spraying too thick or holding the spray too close to the model - When priming miniatures with a rattle can, always ensure that you spray every layer in thin layers, continuously moving the can. Spraying paint too thickly can cause it to pool into recesses and obscure any details within your model or character. Similarly, holding the paint applicator too close to the model can cause a similar effect, so always make sure that you hold the rattle can around 15-20 cm away from the model you are priming. 
  
  
• Priming in cold or humid weather - Always check the weather before you prime with a rattle can, the ideal temperatures for priming will be between 15°C and 27°C. Anything below 15°C will not dry effectively and be too runny when applied to your model, and anything above 27°C  will dry and become gritty before it hits your model. Humidity must also be around 40% - 60% when you are painting, spray priming between these levels will ensure that your paint dries evenly. Too little humidity can mean that the paint will dry too quickly, and when the humidity is too high, your paint will dry too slowly and become tacky. Try to only prime with a rattlecan outdoors when it is within these conditions, if you can’t, consider brush-on or airbrush priming or prime indoors with proper ventilation.