Reddit mentions of Post-it Full Adhesive Roll, 1 in x 400 in, Neon Green (2650-G)

I use a combination of techniques. 3D printed dungeon tiles, dry erase flip mat and tiles. If there is a nice pre-existing gridded map I want to use then I will print it at home.

I use a relatively cheap Ink Jet printer and I added a "continuous ink supply" system (CISS) purchased off eBay. It has paid for itself many times over.

I print the maps full size on many letter sized sheets. Trim the edges as necessary using a ruler and utility knife or something like This.

Next I will use small pieces of Post-It tape to hold the pieces together from the front side.

Finally, I flip the whole thing over and use packing tape along the seams on the back of the map. Then the Post-it tape can be easily removed without tearing up the map or messing with the images at all. You can follow-up by running a glue pen inside the overlap from the top of the map if you wish.

It sounds like a lot of work, but I can generally do a map that spans 8 pages in about 30 min from PC to finished paper map. It's much cheaper then printing at a print shop. After 2 or 3 maps the CISS and supplies pay for themselves. I try to reserve this for larger areas or maps that might be reusable.

Many map makers on Patreon also make modular systems, like forests, cities, etc. I print these out and glue them to 8" x 8" pieces of chipboard or cereal box. They can go together any way you want.