Using Sims 4 Studio, you can quickly and easy allow any custom fur patterns (tattoos) to be used by sims of any age. Most patterns are set to be used only by teen and older sims, but don't require any changes to work well with younger sims except for changing one setting.

My mods generally expect all the SFW tattoos from SoraFoxyTeil's Furry CC to be all ages compatible, which prevents them from being removed from sims that have them when you open the family in CAS and allows you to apply them to all sims directly. This guide works for almost all furry patterns though.

Make sure you have Cyangeom's Sims 4 Furry Mod - For Children, Toddlers, and Infants, otherwise you won't have any furry parts to match the patterns with. You'll also need it's required mod, CAS Unlocks, to actually apply tattoo patterns to younger sims.

Please, please, please do not use this method on any NSFW patterns. It won't break the game, but it might break the law, and your mother's heart, probably.

• Open Sims 4 Studio and press 'My CC' on the right side
• In the new window, navigate to the file where the fur patterns you want to edit are and select one of them.
• In the 'Age & Gender Flags' section on the right, select all the Ages boxes.
• Click 'Apply to All Swatches' in that section.
• Save and repeat for all other fur patterns.