Place strawberries in a bowl and stir in sugar. Allow to macerate for 20 minutes – this will help the berries release more juices and puree smoother.
Pour mixture into a blender and puree until completely smooth*, then pour into a small sauce pan and add lemon juice. Over medium-low heat, stir mixture for 10 minutes to cook off most of the moisture.
Set oven to 170°F, if it won't go that low set it to 200°F but leave the door left slightly ajar.
Spread strawberry mixture onto a parchment lined or silicone lined baking sheet in a even layer about 1/8-1/4" thick.
Depending on the oven temperature, bake for 2-4 hours, checking every 30 minutes after the 2 hour mark. It should be tacky to the touch. If you spread it too thin or baked it too long the leather will be brittle rather than chewy – although it is just as tasty, and can be broken into shards to eat.
Once the leather has cooled, transfer to a cutting board with wax paper, then use a pizza cutter to cut it into strips (leaving the wax paper backing on each strip). Then roll up and store in an airtight container.
*If desired you can press the mixture through a sieve after its been pureed to remove the seeds