# Cels

This section lists some tips for working with the different 3DO graphics types.

- If your title zooms a cel in and out, it is useful to create three or four versions of the cel in different sizes. While a 3DO program can perform a high degree of scaling, the cel looks better if the program can replace a scaled cel with a clean version of the next size after a certain amount of distortion. This technique slows down rendering slightly but greatly enhances picture quality.

- If the number of colors available for a cel is smaller than the number in the source art, you need to reduce the colors before conversion. You can use 3DO Animator and later versions of 3DO PostPro to do this.

- If you have problems aliasing when you display a cel on top of an image, consider using the Anti-Alias CelWriter. Remember, though, that the program has to display both the mask and the cel.

- Do not pack a 16-bit uncoded cel. For this cel type, packing can actually increase file size.