The current study aims to develop and validate the latent factors underlying Korean EFL college students’ enjoyment and boredom, and also explores how these two factors are presented depending on writing task types in an English writing context. This study consists of two experimental phases. Experiment 1 recruited 437 students from diverse majors to investigate writing enjoyment and boredom factors. Experiment 2 employed 71 students to examine the effects of writing task types on emotional variables. They were assigned to two writing task groups: individual continuation writing group (ICWG) and collaborative continuation writing group (CCWG). The results of the study indicate that the following five factors are key to English writing enjoyment: interest and enjoyment in writing, external motivation and learning environment, teacher variables, writing tasks, and interest toward English-speaking cultures. English writing boredom includes five factors: indifference and boredom in writing, low interest in writing tests and tasks, teacher and class atmosphere, anxiety in writing, and indifference toward English-speaking cultures. This study also reveals that learners in the CCWG showed higher enjoyment and lower boredom than those in the ICWG. In addition, CCWG performed better writing achievement than ICWG. Based on the outcomes, pedagogical implications and suggestions are given for L2 writing classrooms.