Hollowing out text from a picture

[shanestensaas]

I am trying to remove the background from a picture in the form of a letter number (see the "e" in the attached photo) but I don't know how to do it aside from taking the "erase brush tool" and outlining the letter by hand. Is there an easier way? If so, please help!! I am using Affinity Photo 1.7.1

Thank you in advance!

Edited July 26, 2019 by shanestensaas
Additional info

[HVDB Photography]

Add a mask layer  and use a black grunge/texture brush to erase
See attachment

encounter.afphoto

 

 

Hubert

 

[shanestensaas]

Hi, thank you for getting back so fast. I'm still new to Affinity but I'm learning a lot! To what would I be adding the mask to?

I hope I was clear in what I was wanting to do. I've added my .afphoto file of what I'm working on. 

help file.afphoto

[shanestensaas]

I'm needing the 4 to be completely transparent when I export as a .png

[Alfred]

Select the ‘4’ layer in the Layers panel and set its blend mode to ‘Erase’.

[shanestensaas]

2 minutes ago, Alfred said:

Select the ‘4’ layer in the Layers panel and set its blend mode to ‘Erase’.

Thank you SOOOOOOOO much! You just helped save a TON of time for me.
Thank you again!!