For a boundaries question involving a supplementary word, first remove that word mentally and identify the complete clauses. Then determine the logical relationship between them. If the second clause explains or specifies the first, a colon may be appropriate; finally, make sure any supplementary word next to that boundary is punctuated correctly.
Hints
- Hint 1
Find the first complete thought
Determine whether the text ending with “process” could stand alone as a sentence.
- Hint 2
Examine the relationship
The statement about interlaced marks explains what makes the process more complex.
- Hint 3
Check the interruption
Consider how a supplementary word placed at the end of a clause should be separated from that clause.
Step-by-step
- Step 1
Identify the sentence units
The words before the blank form an independent clause: “Close inspection points to a more complex process.” The clause beginning with “the gray is produced” explains what that process is.
- Step 2
Punctuate the supplementary word
“However” signals a contrast with the initial appearance described in the previous sentence. Because it is supplementary to the first clause, it must be separated from that clause by a comma.
- Step 3
Introduce the explanation
A colon can follow an independent clause and introduce information that explains it. Therefore, a colon should appear after “however” and before the explanation of how the gray is produced.