Travel Sketches generally are executed in "plein air" rather than in the studio, so they tend to be more spontaneous and may use a variety of media - whatever is portable and available!
Pencil or graphite are easily carried tools for field sketching, and, if you over do it, they can be erased!
Pen and ink, my favorite medium, hence the name Penpoint Studio.
A travel watercolor kit with a special brush allows color to quickly enhance a sketch in the field.
Crayons, pastels, and colored pencils are tools for quick color sketching with varying levels of detail.
2021 Blowing Rock, NC
2008 Moulin des Chennevieres, Giverny, France
1970 - La Purisima Mission, Lompoc, CA
1964 Cityscape, Raleigh, NC