When designing your star map, you have an option to add a frame before checkout. We offer frames with a mat and without. This will not affect the final size of the frame.
The mat is a decorative border placed around a picture to serve as a visual frame or provide contrast between the picture and the real frame. All our mats are "conservation grade", FSC certified, 100% acid-free, and will not discolour or fade with age.
To see some examples of matted and unmatted frames (and find some inspiration, perhaps!) please visit our Instagram account: https://www.instagram.com/underluckystars.
Here is a beautiful example of size 24x36in (60x90cm) star map with "Black frame with mat" option from @nataalee_