How to finish pine which has been cut to make a sign to be placed outdoor.

Hi, we have been asked to make a sign for a house as a Christmas Gift. We have a lovely dark piece of blackwood as the backing board for the sign, and to give the necessary contrast we have used ordinary pine to cut out the letters for the sign. Our concern now is - how do we finish the sign to withstand being placed on the outside of the house, without changing the colour - or at least without making it too much darker.. I have taken a photo of the letters just sitting on a scrap piece of wood about the size of our blackwood backing board, and if I can add the photo here I will. But I often read here of trouble members have of adding photos to their thread, so if no photo appears, it's because I don't know how to add a photo. Thanking you in anticipation of any ideas you may have https://www.woodworkforums.com/images/attach/jpg.gif

A type of marine clear coat for both pine and the Blackwood, would be the most serviceable.

China, is that a paint on product or a spray can product. Thank you for responding to my query.

Normally a paint on, with the proper spray gun it could be sprayed, painting with a brush will give a heavier coat, and more protection

Something like this Feast Watson 500ml Spar Marine Varnish | Bunnings Warehouse

That certainly makes sense. Thanks for that China.

Definitely something with "marine" in the product description from a reputable company (Brolite was my father's favourite years ago) and paint all sides including the back because moisture will sneak in there otherwise.