How many custom fields can we add on sales invoice

Dear Sir, How many custom fields can we add on sales invoice, I tried 7 fields ,but showing only 4 on sales invoice and on printout

I need these fields in printout and will fill manually when customer received goods.

Please check the attached screen shot and all fields are tick marked with " show custom field on printed documents"

You can put all in just 1 custom field. There are already some topics about this, e.g. How to add a signature to the Invoice Template and Custom field on sales invoice not showing on printed document

I recommend you use the search option in top right corner to find more topics if needed.

This is not how custom fields should be used. You can obtain what you need either with a single custom field or with a custom theme.

Custom fields display only when there is content within the fields themselves. You are trying to design a form using the labels of fields. See https://www.manager.io/guides/8941 and https://www.manager.io/guides/13392.