Coloration in Tintypes?

I have upwards of 20 or so tintypes/daguerreotypes, but I am by no means an expert at assessing them. I figured it was worth sharing the two I have that have some coloration. There is some in the boy's cheeks (hard to see here due to my poor documenting skills) and some in the girl's cheeks and flower. I was wondering if there was any particular period where this technique was used? Any info to help date these is much appreciated. Thanks folks

 

https://www.granger.com/results.asp?image=0034411&screenwidth=1024
They do not say if it's a tintype or not?

https://www.ohiohistory.org/learn/c...1/august-2011/what-do-you-know-about-tintypes
Okay, here is some good historical information...and the tinting coincides with the time period of the first link.
(I don't know much at all about this)

 

I "think" that the hand tinting thing has always been since photography started . Probably cost extra . Id guess these were 1870s ,and that girl is truly lovely . Is she wearing a wedding band ?

 

Our local old photo specialist @Figtree3 will have some answers for you too.

 

Her face looks like she's about 11 but the clothing and hands say full adult. The hand tinting has existed for almost as long as photographs have.

 

No wedding band unless it's on middle finger right hand!

 

Welcome to Antiquers, @Cara Lyn !

I agree with @johnnycb09 that coloration of tintypes probably started around the time that tintypes were invented in the 1850s. Not all tintypes had color applied, of course. I found a very detailed study that indicates there was a manual as early as 1861 that gave information on how to color them:
http://resources.conservation-us.org/pmgtopics/2011-volume-fourteen/14-28_Chipman.html

One of my favorite sites for basic information on 19th-century photo processes is Phototree. Here you can find succinct information on the chronology of tintypes and how to identify them:
http://www.phototree.com/id_tin.htm

Although tintypes were used even into the 20th century my own perspective is that the later it got, the less likely it was to find painted/colored tintypes. In very late years they were a cheap format to use, often in photo arcades and tourist sites.
There are also modern tintypists even today.

Here's a lightly colored tintype from my collection.