When and where to use auto vs manual supports in a 3D print.

So you have the proper support settings, but now that you’ve set everything up, how do you approach adding supports to your model?

Automated and manual supports both have their own use cases, but these will depend on the resin and the type of model that you’re using. It’s also important to know when and where manual supports might be necessary.

The main focus of adding supports is to ensure that the model stays attached to the build plate during the printing process, while preventing any distortions within the model itself. In order to achieve this, all islands, overhangs or areas which aren’t attached to the build plate require a support structure. For larger prints, these will often need to be hollowed out to reduce waste. Many newer slicers today use a highlighting system to help draw attention to these areas which will require supportive materials, but this doesn’t always catch every instance.

While slicing software has improved greatly in terms of generating automatic supports, there are certain limitations which are still true today. Large overhang areas tend to have supports in unoptimized areas, and a lack of additional supporting material for the supports themselves.

A main area of concern is the overhangs that cover larger distances, since these are more prone to warping, especially during the first couple of layers. Normally even with automated supports, they do not include enough in certain regions, so these will need to be touched up prior to printing. In most cases, lining any hard edges and corner’s with additional supports should be a major focus, since any warping along those edges will be noticeable in the final print.

Tall and narrow support material tends to be a common issue with automated supports, and these will need to be reinforced to prevent them from bending or failing entirely. Luckily, it’s fairly easy to address this using one of two methods. Either the support pillar diameter can be increased or additional supports can be added to the pillar itself to increase its rigidity.

Placement of automated supports in relation to the model itself can be a tricky issue to address. For highly detailed models where supports need to overlap, there can be issues with these being generated too closely to the model itself. When a model is hollowed out, something in the internal supports can prevent drainage holes from properly draining resin. In most cases, these will need to be moved out of the way. This becomes especially prevalent when a resin is more elastic and prone to bending.

While manually adding supports allows for a greater amount of control over the end product, this can be a time-consuming endeavour. Very important to take into account, is the fact manual supports need to be double-checked for any missed regions and therefore using a validor can aid in this process. For highly detailed projects, I do find that adding manual supports allows me to better control the final product, whereas for more simple projects the automated supports tend to get me 95% of the way done. So while automated supports isn’t a perfect solution, it does provide a good starting point from which to work from.

If you’ve been doing 3D printing for a while now, you’ll probably want to check out my more advanced video, which covers how to model custom supports within a 3D modelling software.



  • Easy to use
  • Saves time
  • Placement isn’t great
  • Requires tweaking


  • Greater control
  • Less Waste
  • Time-consuming
  • Must be double-checked