Dishonored 2

There are a total of 27 collectible paintings to collect in Dishonored 2 for the "Art Collector" trophy / achievement. This is very missable, as there's no tracker to tell you which ones you have, and haven't got. The only indication is when you complete a mission, you can tab over to the "paintings collected" part and it'll tell you if you got all of them. There is no chapter select! This means you have to get all 27 in a single playthrough.

Once you pick up a painting, I recommend making a manual save, or a quick save. The reason being if you die, it won't save the painting and you may forgot you picked it up. Always check you got all of the paintings on the mission summary screen!

I am putting instructions on each painting of how to access them without powers, which is certainly the challenge you would expect. Getting there with Blink or Far Reach is a lot easier and does not really need any separate instructions.

MISSION 1: A Long Day in Dunwall
Curtis, Morgan And The Postulate Child: Found in the tunnel exiting from the palace to the streets.
The Obtuse Arguments Of Lady Boyle: Found in Galvani's office, building on the left near some bushes, above the fireplace.

MISSION 2: Edge of the World
High Overseer Thaddeus Campbell: Found in a third floor apartment in the first area. You can Blink or Far Reach up there. If you are doing no powers, you need to start your climb near the wooden path up the steps near the whale. Climb onto an AC unit to a balcony. Loot the apartment up here if you want. Continue climbing things until you need to make a daring jump from a balcony to a jutting metal beam and from there to a fan. Climb onto the next balcony from the fan. Get down the same way you got up.
The Outsider In Conditional Dreams: Near the wall of light is an apartment with a ground floor entrance. If you look inside the door, you will find a guard and an Overseer standing there. Another Overseer is inside the upstairs apartment.
The Vice Overseer’s Predicate Logic: 3rd floor of Overseer building. If you don't have powers, climb up the undefended first two floors and be careful as you take care of the Overseers upstairs. You may have better luck than I did getting onto a balcony from the security booth, but that only gets you to the 2nd floor.
Hypatia’s Protective Gaze: Hypatia's apartment above the Winslow Safe Company (just past the train tracks) has this one. The key is in the Safe Company.

MISSION 3: The Good Doctor
Duke Abele’s Propositional State: Right next to the Wall of Light in the room inside the main entrance of the Addermire Institute.
Anton Sokolov In Subtractive Light: This one is in the basement. Get there by breaking the elevator cables in the shaft. You should do this from level 2, because it's easier to get down safely (if you call the elevator to level 1.) Once it crashes down below, carefully head down there and the painting is on the left.
I Regard Her, Within and Without: In Hypatia's area, this is in a lab with a blueprint.

MISSION 4: The Clockwork Mansion
Ramsey's Stochastic Eyes: For this one, you really need to be sure that all of the guards on the street are taken care of if you don't have powers. You need to climb onto a light next to the security booth and from there onto a building with a big ad on it that allows you to climb higher to the balcony that leads to the room where this painting is on the wall.
The Spymaster’s Axis Of Asymmetry: From the alley across from your starting position, go upstairs to a blocked, but breakable, door. If you don't have powers, you will need to blow the door down with a grenade. The painting is in the far room with the balcony.
Jindosh Considers An Odd Numerator: In the Upper Aventa District, get past the Wall of Light. The way to do this is through the building just past the gate code platform. The whale oil thing is on the second floor and the guy with the code to the gate, and the key to a nearby other gate, is on the third floor. Once past the Wall, go left and look for an awning. Near there is a building that you can climb up into to access the balconies above. Get onto the balcony closest to the awning and jump to a balcony on your left. From there, jump to the awning and take care of the bloodflies within before you enter to get this painting.
I Look Upon The Craftsman: In the room with the bed and the balcony, stand on the platform with the bed while you pull the lever. Get off at the destination and pull the lever again. When a bathtub comes into view stand on the platform with the lever and pull it. The painting is in the new room. The door here leads to the lab, but they will be waiting for you if you go this way.
The Blood Topology Of Grim Alex: This one is in Sokolov's room in the Assessment Chamber, however you get down there.
Light Along The Inverse Curve: This one is on the second level of Jindosh's lab, most easily found by going all the way to the top of the second elevator.

MISSION 5: The Royal Conservatory
Ashworth Within An Existential Graph: Get to the roof of the red building just past the Wall of Light and make note of the bloodflies across the street before getting over to that balcony. There is a guy to the left by the desk. The painting is over there with the safe you may have purchased the combination to.
I suggest, at this point, you take care of Breanna with or without the nonlethal option. Still get the lenses from the fourth floor. The machine still knocks out every witch you dd not encounter and destroys all of the magical plants, even if you kill Breanna first. It may not kill all of the Gravehounds, so be careful.
My Fires Burn Within Breanna’s Marrow: This one is in Breanna's Office, inside the Conservatory.
Her Heart, I Bathed In Poison: This one is in the Conservatory basement Archives, accessible with a key found in the basement office accessible from a ground level courtyard window.

MISSION 6: Dust District
Paolo and the Inaccessible Cardinal: On the second floor of the Crone's Hand Saloon in Howler territory.
Vera Moray And The Affix Of Her Skin: On the second floor of the Crone's Hand Saloon in Howler territory. It's in a bathroom with a shrine.
Indiscrete Time Finds Aramis Stilton: From the fourth floor of the Overseer building, climb through the broken window on the right and follow the right ledge to the next broken window at the end. The painting is in there, past an audiograph.

MISSION 7: A Crack in the Slab
The Commutative Rats And The Weeper: This one is in the safe that is in a hallway from the Dining Room where you get the Master Key.
The Torturer’s Quaternionic Groan: In the present, go up the dirt hill in the open room with the bloodflies on the balcony. Clear them out and look in the room with a suitcase for a window with a note. Go back in time and kill the workers and the guard. This allows the window to be gone in the present. This leads to the room with the breakable balcony. Break it in the past and climb up in the present, go straight ahead and look to the right for two leaning bookshelves. Go to the past and the painting will be in this room where the face-down canvas is in the present.

MISSION 8: The Grand Palace
Daud and The Parabola of Lost Seasons: On the side of the street where you find the Winslow shop, at the end near the Watchtower is an apartment complex. On the roof is a windmill, you need to get down to the balcony with the bloodflies and take out all of the bloodflies. The painting is in the back room.
My Name On Their Lips: On the third floor of the palace, in a room with a piano, you will find this one.
Her Face Is My Smile: Also on the third floor, in an office room with a clockwork, is this painting.

MISSION 9: Death to the Empress
Luca, His Eyes Upon Me: In the yard below the gazebo, past some Gravehounds, you will find this one.