I don’t offer a framing service but all the portrait sizes are standard so you can buy off-the-shelf frames.
They are not glass, but having two young boys I much prefer this safer option.
For a bespoke frame if your ordering triple portraits or more, then FRAMES UK is also great..
Desenio have a really stylish selection of thin wooden and metal frames. They come in a variety of colours and sizes and work really nicely with any portrait size. You can either frame them to the edge of the frame, or add a picture mount depending on the type of look you want to create with your finished portrait.