1. Issue
It is supposed that Father Rougier was the designer of this stamp.
The stamp shows the company schooner "Ysabel May" (of 135 tons) which is greeted by a Bosun Bird while approaching Christmas Island.
1916 until December 1923 -- 5c blue, orange, red, green and black, the value tablets in carmine.

1st issue used AUG 31 1916
(new 2/2021)
Earliest know use: snippet with 1. issue used 31 AUG 1916 with CL1, extra date cancel and Papeete postmark 25 SEPT 16.
I think that these 31 AUG 1916 stamps are from letters Rougier prepared on his first institutional visit on the island to be sent to philatelic magazines and stamp papers.
Contemporary papers wrote that the stamps were in use 1916. (image source: seller "tazzmann30" on Ebay.)

1st issue used AUG 31 1916
(new 10/2018)
Earliest know use: 1. issue used 31 AUG 1916 with CL1 and extra date cancel

the AUG 31 1916 postmarks
(new 2/2021)
Comparison of the two postmarks: yes, they are identical.

A 1916 postmarks
(new 3/2023)
Comparison of the two postmarks: yes, they are identical.

26 April 1917 Cook Islands
Rarotonga cancel
26 April 1917 Cook Islands
Rarotonga cancel (Per-Arne Hansen coll.)

Cook Islands
Rarotonga postmark type
Must have been this type of postmark

1st issue used
(new 12/2018)
1. issue used with CL1, pos 1,1. Only the second one I've seen with CL1 horizontal

1st issue used
(new 3/2019)
A rather battered copy with part of a Papeete postmark

1st issue pos 2,2 misperf.
(new Sep 2018)
1. issue pos 2,2 - heavily misperforated

1st issue pos 1,1
(new Dec 2018)
1. issue pos 1,1

1st issue pos 2,2
(new Dec 2018)
1. issue pos 2,2

1st issue pos 2,1
(new March 2019)
1. issue pos 2,1 possibly

1st issue pos 2,2
1. issue pos 2,2

1st issue pos 2,2
(new March 2020)
1. issue pos 2,2

1st issue pos 2,1
(new March 2020)
1. issue pos 2,1 possibly

1st issue pos 1,1
(new May 2022)
1. issue pos 1,1

1. issue
1. issue - 1916
No watermark, line perforation 11¾ or 12½
← at left the complete sheet
two singles at right →

perf 1. issue
perf. 1. issue

perf 1. issue
perf. 1. issue

1. issue, pos 2,2

1. issue, pos 1,1
1. issue - 1916 pos 1,1
Image thanks to Delcampe

1. issue
1. issue - 1916
Image showm in the 1998 Boslu articel (see lierature)

1. issue

1. issue
1. issue - 1916 - Source: Ebay
.

1. issue
(new Feb 2018)

1. issue
(new Feb 2018)

1. issue

1. issue
1. issue - block of four - (David Gillis coll.)
.

1. issue
(new 6/2019)

1. issue
(new April 2022)
1. issue - 1916

1. Issue block of four
(new 1/2020)
1. Issue - block of four without selvedge.

1. issue 16 June 1918
1. issue used cancelled Papeete - (David Gilliscoll.)

1. issue cut or imperf at top
(new 1/2025)
1. issue cut at top or imperf?
There may have been a second printing of the 1. issue - Details still have to be investigated!
James Mulik found a nice variety recently: A stamp with heavily shifted blue color. This error is quite scarce - it's the only one I have seen so far.

Blue shifted downwards
Blue shifted downwards

Color extracted (b/w image)
Color blue extracted (b/w image)

The plate
The plate
In 1919 and 1921 stamps of the 1. issue are know
cancelled in manuscript. (Sorry for the poor image quality)

manuscript date
Nov 1921
1. issue manuscript date

manuscript date
1921
1. issue manuscript date

manuscript date
21/4/21
1. issue manuscript date 21/4/21 Papeete.
Image thanks to Per-Arno Hansen.

manuscript date
11 Nov 1921
1. issue manuscript date

manuscript date 1919
1. issue manuscript date 1919

1. issue with Rougier sig. and a
1921 date (new 1/2020)
1. issue - cancelled single on piece of a printed document, manuscript date 1921 and a signature of Rougier

manuscript date
3 Oct 1921 (new 6/21)

yellow shift upwards
(new 1/2025)
1. issue with yellow shift upwards

Color shift and bad centering were quite common with this issue.
(new 3/2025)
1. issue with yellow shift upwards and bad centering
1. issue: The flaws
They help to identify the plate position of single stamps. Please make sure that your stamp is a 1. issue one: has it a broad not printed area round the
actual printed image? Is the colour orange and not yelloworange?

The main flaws - 1. issue
the main flaws - 1. issue
It is rather difficult to find real plate flaws as there are many printing randomnesses too like little red dots etc.
When you try to identify a position with this issue you can look at the following images - maybe they can help you.

pos 1,2
pos 2,1

sail pos 1,1
pos 1,1

sail pos 2,1
pos 2,1

sail pos 2,2
pos 2,2
Wide gap between top of right sail and mast: pos. 1,2. Compare with the same part at the other positons.
Remember: you can click all images and place the blow ups
side by side with the mouse so you can compare better.

green pos 1,2
pos 2,1

green pos 1,1
pos 1,1

green pos 2,1
pos 2,1

green pos 2,2
pos 2,2
Here another constant plate flaw for pos. 1-2: there is more green to the left and right of the right wing of the bird. Easy to see when you have
all plate positions together but not so easy on a single stamp. Maybe these pictures will help.

pos 1,1
pos 1,1
#1: Red dash below left small palm and horizon: the stamp is from left or right pos. 1,1.

pos 1,2
pos 1,2
#2: Wide gap between top of left sail : stamp from right pane pos. 1,2.
#2: More green on both sides of the bird's rightwing: stamp from right pane pos. 1,2.

pos 1,2
pos 1,2

pos 2,1
pos 2,1
Sorry - I found nothing until now!

pos 2,2
pos 2,2
#4: dot above head of bird: the stamp is from pos. 2,2.