I was going to make one, but then read what Bonnie Hunter suggested...it was way easier 😊. I bought a June Tailor cut and press thingie and sewed up the sides of a bath towel to make a "pillowcase" for it. The terry cloth protects the ironing surface and can be tossed in the washer/dryer when it gets grubby.
I have never used the cutting side...I stick my 12x18 mat in the sack, along with any rulers I might need, to tote along when necessary.
We live in our rv, so this is what I mostly use for an ironing surface. It fits nicely on a tv table and I keep it next to me when I'm sewing, but drag it along to the clubhouse or guild when needed.
Margaret