I seal all print and cut images with Krylon Artist Spray to protect the images from smudges, moisture, etc. Artist spray is different than varnish or other wood sealers. Make sure you read the label to make sure the sealer used is intended to sealing artwork, is acid free and non-yellowing.
Sealers I Recommend for Sealing Print and Cut
Krylon Matte Finish 1311
The matte finish Krylon Artist Spray is great for all papers. I have not found it to discolor paper. I also use this when I print and cut on texted paper like Bazzill Canvas paper.
Krylon Crystal Clear Acrylic Coating 1303
This is a gloss finish, the more applications you apply the glossier it will be. Additional drying time is required for Crystal Krylon, especially as additional coats are applied.
How To Seal Printed Images for Print and Cut
The easiest way to seal printed images is to seal the entire printed page prior to being cut. By sealing the entire page, you don’t have worry about die cuts blowing around while you are trying to spray the pieces. After spraying the entire page, allow the page to dry completely before cutting. If you cut prior to drying, it can cause issues with cutting like tearing or ripping. If you will be using the sealers I recommend, drying time is only a few minutes. The Crystal Krylon spray may require more drying time.
Always seal printed images outside. Do not use the sealing spray in the house and never spray it near electronic die cutters.