how to preserve custom format in Numbers

Create a blank document with all the custom cell formats and custom table formats and other custom formatting you like, then save it as a template (File/Save as Template). Use that template when creating new documents and your custom formatting will all be there.

I see. I am not aware of any way to make a "global" style like the built-in ones.

While it doesn't 100% meet your request, instead of recreating a style each time, you can copy a style from another document and paste it into your newly imported document. One method would be to create a document that has all your custom cell styles in it, with a column of examples of each one (i.e., cells that are formatted with each style). Select a cell, use "copy style" to copy the style, go to your newly imported document, select the cells where you want the style, use "paste style" to paste it in. Your custom style will now be part of the new document. One of the edits I made to my Numbers toolbar was to include the Copy Style and Paste Style icons but you could use the menu items (under the Format menu) or the keyboard shortcuts (which you can find in the Format menu).

The downside to using copy/paste style is that it copy/pastes everything style related, including font and text size and justification and all. These may not match what is in your imported document.

Hi Ramon,

Follow Badunit's instructions to create a template containing your custom formats.

Click once on a cell formatted with a custom format and Copy.

Go to any document and click once on a spare cell. Paste (no need for copy/paste style).

Your custom format will magically appear under Format Panel > Cell > Data Format

Select the cells where you want to apply the custom format

The custom format is applied without any other formatting (no Comic Sans font!).

Regards,

Ian.

Good tip. That also solves the problem of it pasting all the rest of the style to the cells, most of which would probably be unwanted.