Mix the sugar and gelatin (or cellulose gum) together until well combined.
Bring 3 cups of water to a simmer. Do not bring to a boil. Add the sugar/gelatin and mix until dissolved. When fully dissolved, turn off the heat. Let it cool completely, then chill in the refrigerator for 1-2 hours to raise the viscosity.
Meanwhile, squeeze enough limes to make 1 cup of lime juice. Use less if you don't like it too sour (I like my lime paletas more on the sour side). Keep cool in the fridge while you wait for the base to thicken.*If you don't want any pulp, make sure you strain your lime juice. I don't mind the pulp (it's not that much), so I just left it in.
The base is thick enough when it has a similar consistency to syrup.
Add the lime juice and mix thoroughly. Taste to see if you need to make any adjustments.
Optional: add food coloring to make it a lime green color. I tried doing this with natural ingredients with good (not great) results! Spinach juice works but doesn't give you the vibrant neon color that food coloring can achieve. I used some green and yellow food coloring from Sprouts that were labeled as "no artificial food dyes." It worked really well!
It depends on your popsicle mold, but be mindful about the popsicle stick placement when you're sticking them into the mold. You don't want to push them all the way down because it leaves very little room to hold the stick, but you also want to make sure its deep enough. Also make sure it is centered from all sides.
Freeze for at least 8 hours. To loosen, you can place the mold into warm water for about 20 seconds, or you can use a popsicle stick and push it down the sides of the mold to loosen the paletas.
Eat right away and try not to let them sit out at room temperature too long. These are the perfect texture when just frozen!