MOC Instructions Printing: A4 vs A3 Sizes and Settings
The short answer first: choose your MOC instruction print size based on how detailed the drawings are and how many pieces the model has. Under 1,500 pieces, A4 is enough. Above 1,500 pieces, go with A3. When you print, always select "Actual size" at 100% scaling — if the scale is off, part dimensions drift and the build will not line up.
Step 1: Decide between A4 and A3. A4 paper measures 210 × 297 mm. It suits small MOCs with simple step diagrams and fewer than 10 parts shown per step. A3 measures 297 × 420 mm, which gives you twice the area of A4 — a better fit for large, part-dense instructions. A simple rule of thumb: if a single step shows more than 15 parts, or the model totals more than 1,500 pieces, pick A3. Otherwise the small callouts and fine details smudge together into an unreadable blur.
Step 2: Set the correct scaling. This is the step that matters most. In the print dialog, always choose "Actual size" or "100%" — never "Fit to page," which silently shrinks the drawing and distorts part proportions. If you are printing a PDF downloaded from brickplan, preview page one before you send the job: measure the width of an illustrated part with a ruler and compare it against the real brick. The error should be within 1 mm.
Step 3: Pick the right paper and print method. For everyday building, standard 80 gsm copy paper is enough. If you will flip through the pages again and again over time, use coated paper of 120 gsm or heavier. For color instructions, inkjet printing keeps the fine lines sharper. For black-and-white instructions, laser printing is faster and shrugs off moisture. Cost per sheet runs about CNY 0.5 for A4 and CNY 1 for A3. A set of instructions for a 2,000-piece model is usually 12 to 20 pages, so the whole job comes to roughly CNY 10 to 20.
Step 4: Bind and store them. After printing, stack the pages in step order and bind them with binder clips or a ring binder — pages turn easily and the stack will not fall apart. Write the total part count and the completion date in the blank margin of the first page so you can review the build later. In humid regions, drop a packet of desiccant into the storage box; keeping the paper flat and curl-free can more than double how long your instructions last. Keep a digital copy on a tablet as a backup, so if the paper version gets stained or lost you can reprint immediately instead of waiting on a delivery.
FAQ
Q: How do I choose a print size that keeps MOC instructions clear? A: Under 1,500 pieces, use A4; above that, use A3. The deciding factor is parts per step — more than 15 parts in a single step means A3. Print at 100% actual size and use paper of 80 gsm or heavier, and the lines will be sharp enough.
Q: What if the parts on my printout are the wrong size? A: In most cases "Fit to page" was selected and the drawing was scaled. Reprint and choose "Actual size" or 100% scaling. Before printing, check page one with a ruler against a real part and keep the error within 1 mm, and the build will go together normally.
Q: Is there a difference between color and black-and-white printing? A: Yes. Color instructions printed on an inkjet keep more detail and work well for steps where color distinctions matter. Black-and-white instructions are cheaper and more water-resistant on a laser printer. As long as part numbers and outlines are legible, black and white builds fine.
Q: How much does it cost to print a full set of instructions? A: At home, A4 runs about CNY 0.5 per sheet and A3 about CNY 1. Instructions for a 2,000-piece model are roughly 12 to 20 pages, so the total is CNY 10 to 20. A print shop is cheaper for bulk jobs — print everything in one go to avoid color shifts between batches.
Q: What should I watch out for at a print shop? A: Tell them up front that you need 100% scale, and confirm the file is a PDF so the layout will not scramble. Check the part dimensions on the first page on the spot when you pick it up. If it has been scaled, ask for a reprint right away rather than discovering it halfway through the build at home.