Testbulb

Testbulb is the femslash ship between Test Tube and Lightbulb from the Inanimate Insanity fandom.

Inanimate Insanity 2
Paintbrush says that Test Tube can build their rocket, and Lightbulb asks what makes them think she's qualified to do that. Paintbrush says that test tubes tend to be used for scientific purposes, and rockets are sciency stuff. Lightbulb then asks Test Tube if she could build the rocket, and tells her to try her best. Test Tube immediately goes to build the rocket, and does it in seconds, amazing Lightbulb.

In "Afterlife in the Limelight", when Bow sings "Taking part in the action, made for easy interactions with friends", Test Tube is seen trying to give the bucket to Lightbulb, but Lightbulb throws the bucket and Test Tube into the water.

Lightbulb runs in Test Tube's laboratory with three cans of Dr. Fizz, asking Test Tube how much she owed her for the three of those, and says that she's gonna splurge today. Test Tube angrily rips up the "Test Tube's Secret Laboratory" sign and says that she should start charging admission now. Lightbulb apologizes, and says that she drinks when she's depressed, which she quickly adds that she's not. Lightbulb drinks a can of Dr. Fizz and coughs up Baxter(Lightbulb's crab). She says that she's found him and would give him one too, but he wasn't depressed. Then, she asks her how much did she owe for those things. and picks up a calculator, and presses some buttons, not knowing that it is actually a time machine. Test Tube says that it wasn't ready yet, and Lightbulb says that it's ridiculous, but before she can finish her sentence, a portal appears out of nowhere and sucks her, Test Tube, and Baxter up.

Lightbulb, Test Tube, and Baxter suddenly appear in the middle of the events of The Crappy Cliff(the first ever episode of Inanimate Insanity). Test Tube is happy that her time machine worked. Lightbulb asks if she divided by zero again, and Test Tube scolds her, saying "Do you know where you've just taken us!?" but then asking her where she has taken them, since she's never been there before.

Past-MePhone4 explains the challenge, jumping off a 50-foot cliff. Lightbulb explains the challenge to Test Tube, who is unimpressed and questions the lifelessness of the past contestants. As the challenge begins, Lightbulb waves at past-Paintbrush, prompting them to ask a question. Test Tube quickly stops Lightbulb, explaining she shouldn't interfere with the past in any way, even breaking on a twig. As if on cue, Test Tube then accidentally breaks a twig and frantically starts to fix it. Lightbulb, upon hearing past-Salt and past-Pepper's conversation, frowns and starts to walk in their direction.

Past-Salt and past-Pepper repeat their conversation about cliff jumping, but are interrupted by Lightbulb, who gives them a pep talk and then pushes them off the cliff and into the water, causing them to win the contest, and therefore, pick the teams. Lightbulb cheers at first but then realizes what she had done. Test Tube, who melded together the twig she broke, runs over in a panic, not sure if that the events were supposed to happen or not. Lightbulb then says that it actually wasn't supposed to happen and Test Tube, panicking more, gets out her time machine, hoping that the present didn't change too much.

The time machine activates and Test Tube and Lightbulb appear in Inanimate Insanity Infinity, and are immediately met by Thermos, who screams loudly, and Frank, who calmly welcomes them. Lightbulb, unfazed, reassures a shocked Test Tube that this seemed right. A spotlight suddenly opens on Salt and Pepper, who begin to introduce their show, but seem to forget the name. Chives, their assistant, tediously reminds them of the name, and the two finally remember, and introduce Inanimate Insanity Infinity, followed by their own curated intro.

Lightbulb and Test Tube are met by Kumquat, who excitedly welcomes them in a fast and erratic manner. Test Tube notes the strangeness of the new universe, upsetting Shell, who notes that it's supposed to be appealing but is still looking for new ideas. A darkness overshadows the group as an echoing voice is heard, revealed to be Black Hole, who complains that they don't get enough screen time, shocking Test Tube and ticking off Red Light. Bandana spots the new duo and questions if MePhone7 asked for them. MePhone7 responds simply by violently shaking and buzzing, which Hay Bale surely interprets as a "yes". Test Tube, still perplexed by the new universe, begins to have a breakdown, while Lightbulb misinterprets this to break the Time Machine.

Salt and Pepper then decide to have their own exclusive challenge, a fashion show, created by MePhone7. The other contestants complain that they can't even participate. Lightbulb happily tells them not to fret and that they can get attention as a team, who agree to do so after meeting Baxter. Test Tube, in utter disbelief, argues that they shouldn't even be real. Lightbulb decides that this reality may be better, much to Test Tube's anger. The rest of the contestants take off with Lightbulb to engage in fun activities, leaving Test Tube alone.

Later, atop a Salt and Pepper shaped mountain, Lightbulb recalls her talk with Paintbrush and vents to the contestants, who blindly agree with her. Lightbulb then complains about Test Tube also upset with her, though Kumquat brushes it off and blames her emotions, noting her as one of "those ones", prompting Lightbulb to worry. Meanwhile, Test Tube is alone working on her Time Machine and is confronted by Salt and Pepper, who are suspicious of her. After explaining that Test Tube rational mind doesn't fit into their algorithm, they order Chives to tie her up and drags her to the elimination area.

As "Elimination Time!" begins, all contestants and Lightbulb are summoned to the elimination area to witness Test Tube tied to a pole. Salt and Pepper irrefutably decide that Test Tube is eliminated, much to the delight of the contestants, though shocking Lightbulb. Salt and Pepper then give Test Tube the choice between two portals; she may enter Black Hole and be permanently eliminated, or enter a smaller Pink Hole, which would take her back to choose between the two options again, causing a never-ending chain that would eventually end with Option 1. As Test Tube argues against the brutal elimination, Lightbulb steps forward, advocating that this has gone too far, though Hay Bale and Kumquat find this humorous and laugh at her. Test Tube, now frustrated, yells at Lightbulb for being able to solve problems with her quirks and nonsensicality, deeply upsetting Lightbulb.

Salt cuts the two off for taking up too much of their fame. Lightbulb concurs and notes that Salt's fashion show is more important, provoking Pepper to correct Lightbulb that the fashion show was both of theirs. Lightbulb disagrees and begins to demean Pepper and praise Salt as a leader, while Test Tube joins in the bantering, angering Pepper yet appealing to Salt, who agrees that Pepper merely latched onto her. In a fit of anger, Pepper punches Salt, knocking her into Black Hole. The contestants cheer in delight while Test Tube and Lightbulb stand in shock, quickly fixing the Time Machine with Lightbulb's electricity and travel back to The Crappy Cliff.

After Test Tube forgives Lightbulb and they begin to see eye-to-eye, they figure out a plan to fix time and correct everything back as it used to be. Using Test Tube's liquid, they turn Baxter bright green; Lightbulb tosses Baxter into the water, where past-Salt and past-Pepper are. Test Tube, hiding in a bush, shouts out a fake warning to the others, frightening them of Baxter. Lightbulb demands past-MePhone4 shoots a retake, causing Salt and Pepper to redo their jumps, setting everything back to normal. Test Tube and Lightbulb then return back to the present.

With only ten seconds left, Lightbulb and Test Tube run in and quickly paint something, Test Tube paints a moon, and Lightbulb takes her painting she did at Inanimate Insanity Infinity, and puts it on the stand.

At the elimination, Paintbrush is eliminated, with three votes. As they walk into the Rejection Portal, they look at Lightbulb, Test Tube, and Fan, and smiles. After Paintbrush walks into the portal, Lightbulb is seen leaning on Test Tube, with Test Tube putting her hand on Lightbulb's back.

When Fan is recording a recap of the last episode, Test Tube and Lightbulb are seen exploring a cave. Lightbulb stumbles upon and befriends a purple robotic arm while Test Tube detects a high energy gem and walks up to touch it.

In the present, Lightbulb attempts to wake up Test Tube and holds up her hand to ask how many fingers she was holding up, only to realize she couldn't hold up any fingers, and asks who did this to her. Lightbulb sees MePad and Toilet and runs to them, telling them that Test Tube found a gemory in the cave, and says that she keeps talking about corn. Lightbulb says that she loves sparkly gems as the next guy or girl, so she can't complain.

Lightbulb dresses up as a pirate, digging up a red X on the ground, saying that X marks the spot, and MePhone is not fooling anyone with his cage mining coverup. Test Tube is seen smiling at her.

Test Tube says that Fan was taken by none other than Cobs, and that makes us angry. Lightbulb, along with everyone else, agrees. Test Tube says that they must channel all their anger in and save him, and asks if who's with her. Lightbulb, along with everyone else, agrees.

Test Tube rants to Lightbulb about Suitcase making her the villain even though she was doing the right thing. Lightbulb snatches the hammer that she was holding, and apologizes to her with tears in her eyes. She then smashes part of the rocket wing Test Tube was working on, startling and confusing her. Lightbulb says that that was her at Fan's elimination. Test Tube says that she didn't smash anything, and tells her to look at all the damage she just caused. Lightbulb then proclaims it's not just about what you do, but also HOW you do it. Test Tube smiles and thanks her, then demands that Lightbulb go get some tape to fix the wing. Lightbulb, surprised by her own damage, departs, leaving Test Tube to gaze up at the Egg Spaceship and reassure Fan they were almost there.

Lightbulb is then seen with a beret, a palette, and a paintbrush. Test Tube walks over to her, and Lightbulb says that she named the rocket wing a flying buddy. She tells Test Tube that she can have a flying buddy, and says that she would, but she already has one, and that she's got plenty. Test Tube smiles at her, and walks away smiling.

Test Tube is carrying an unconscious Fan, saying to Microphone that she hopes that it was worth it. Lightbulb walks over to her and puts her hand on Test Tube's chest, and walks away with her.

Test Tube says to Fan that she trusts him, and that we got this. Lightbulb suddenly appears, saying "Yeah lights! We got this! Except... now it's lights out for both of you because you're both eliminated." Lightbulb sighs, and then whines, and says that she didn't give you both permission to do that. Test Tube says that they still have their brightest light in the game, and points her finger at Lightbulb. Lightbulb says that the bright puns are being a little overplayed, but she appreciates the sentiment, and puts her hand on Test Tube's back. Test Tube says to Lightbulb to stir up some chaos for her, and puts her hand on Lightbulb's back. As Test Tube and Fan walk into the Rejection Portal, they look at Lightbulb, and smiles. After Test Tube and Fan walk into the portal, Lightbulb smiles, and then frowns.

Fanon
is the most popular femslash ship within the Inanimate Insanity fandom, and also the second most popular ship for Test Tube and Lightbulb. It became popular because of Inanimate Insanity S2E12, "Alternate Reality Show". The pairing rivals Test Tube's most popular ship, Fantube (Fan/Test Tube) and Lightbulb's most popular ship, Lightbrush (Lightbulb/Paintbrush). It is often shipped paired with Fanbrush (Fan/Paintbrush).

On AO3, has 5+ works, and is the second most written ship for both Test Tube and Lightbulb.

Fandom
FAN FICTION

TUMBLR

Trivia

 * Test Tube and Lightbulb are both made out of glass
 * Their emoji combo is 🧪💡