I have made several portable pressing boards. I use them when I teach for guilds,  or when I go to a quilting retreat or in my sewing-office for smaller proyects or for a very big project that needs pressing in a small area and I do not want to carry the entire project to the regular ironing board. These are light weight easy to pack and carry.

I used a piece of aluminum laminated insulation board like the one shown below

You can also use blue insulation boards like these

BLUE INSULATION BOARD

Blue insulation boards

Use a utility knife to cut a piece the size you want

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A piece of Aluminum laminated insulation board

Make sure it is clean, these boards come from dusty places.

Cover the board with two layers of batting

PORTABLE PRESSING BOARD-0003

Batting covered board